For any trainer, evolving their Pokemon is a key component of the game. It's a sign both that their partners are getting stronger, but that the trainer themself is getting stronger. Evolving a team of Pokemon is a sign of making progress through the world as much as collecting gym badges. When tackling the Elite Four with a fully-evolved team of six, it's satisfying. Even the weakest fully-evolved Pokemon are still emotionally significant.
However, with Pokemon there's an awkward stage of evolution that is rarely remembered: the second stage. These second-stage evolutions are more powerful than their base forms, but fulfill a transitional period. As such, some are better than others in both design and statwise. There are some truly terrible second-stage evolutions, and some that are more just thoroughly mediocre compared to others. Trainers may be surprised to see that there are some patterns in how Game Freak selects base stat totals for Pokemon as the numbers count down.
10 Pidgeotto - 349 BST
The evolution of the original Route 1 Bird, Pidgeotto is a key member of a few significant character's teams. Pidgeotto is the ace Pokemon of the gym leader Falkner, and was an important ally on Ash's team during his Indigo League challenge. Trainers likely have fond memories of this bird, and it does have a pretty cool design fitting of its spot.
Although its base stat total is below average for second-stage Pokemon, it isn't the absolute worst in the game. It still has decent speed and attack, allowing it to be a threat to first-stage evolutions that it battles during much of the game. While some flying Pokemon are a complete mystery, Pidgeotto is pretty much exactly what a trainer would expect.
9 Staravia - 340 BST
Another Route 1 Bird's second stage, Staravia is for some reason slightly weaker than Pidgeotto. However, that weakness is just in the raw number of the base stat total. By comparison, Staravia is a lot more competent and prepared to hold its own until it reaches its mighty final stage of Staraptor.
Staravia is even more focused on offense than Pidgeotto, having more attack and speed in exchange for weaker defenses. This makes Staravia terrible at taking hits before it evolves, but it can at least hold its own offensively during the awkward middle stage. Plus, the little curl on its head is pretty adorable.
8 Nuzleaf - 340 BST
One of several Pokemon sitting at 340 base stat total, Nuzleaf is the second-stage evolution of Seedot. However, unlike birds like Pidgeotto, it requires a Leaf Stone to evolve, making it harder to evolve than other Pokemon it sits tied with. It shares this trait with Lombre, which is also on the list. Even fully-evolved though, both are far from the strongest in Gen 3.
Nuzleaf is a distinct upgrade from the relatively weak Seedot, and an upgrade picked up early on. More interestingly, Nuzleaf picks up the dark-type, giving it secondary typing that has its strengths and weaknesses. The typing isn't quite as good as Lombre, but still works fine. Nuzleaf is best used offensively, but can be evolved at any time to become a much more effective Pokemon.
7 Lombre - 340 BST
As stated before, Lombre ties Nuzleaf in base stat total. As it serves a similar role, it makes sense the two would match. Lombre is the second-stage evolution of Lotad, the Pokemon Sapphire exclusive early game grass-type. While it keeps its typing between phases, Lotad wasn't lacking in moves the same way Seedot does.
Lombre evolves using a Water Stone, which is found shockingly late into the main adventure in Pokemon Sapphire. For trainers who enjoyed the design of Lombre and Ludicolo, they might be sitting on Lombre longer than any trainer should. At the very least, its stats don't leave it with any glaring weaknesses, but not many strengths either.
6 Vibrava - 340 BST
Another Gen 3 Pokemon, this one might be a bit of a surprise to some trainers. Although the final stage isn't quite a pseudo-legendary, Flygon has its place as a powerful dragon-type with its own niche and a variety of movesets. Trapinch, the base form, is kind of just terrible while Vibrava isn't much better.
Vibrava shares a statline similar to Pidgeotto and Staravia, focusing on speed and attack over any other stat. Even so, Trapinch actually has a higher attack than Vibrava does. That's right, Vibrava has a stat that decreases when it evolves in exchange to be slightly more mediocre across the board. Vibrava also takes some time to evolve, so it's quite the investment.
5 Skiploom - 340 BST
It honestly isn't a surprise to see the second-stage of Hoppip on a list of Pokemon with bad stats. The whole evolutionary line is just sad, with the final stage in Jumpluff not even being that great compared to just Gen 2 grass-types. As such, Skiploom being terrible just makes sense.
Skiploom doesn't have a lot going for it. It has a fair bit of speed to it, allowing it to run away from all the Pokemon that can absolutely body it. Ice-type Pokemon in particular enjoy seeing this floating flower roaming the skies. It would be recommended to evolve it as soon as possible, but the reality is more to just abandon all hope with Skiploom. It's not a Pokemon that gets away with "just being cute."
4 Dottler - 335 BST
Of the new Pokemon added in Sword and Shield, Dottler likely came as a shock to many trainers. First, its typing is unexpected the evolution of a Route 1 Bug. Second, its stats aren't completely awful across the board like other second-stages of bugs. It isn't good, and Charjabug is still the best in this particular category, but it is far from the worst.
Dottler, like other second-stage bugs, is focused more on defensive stats than offensive stats. Both of its defenses are pretty solid as well, making it an effective wall for early in the game. It even has a collection of solid attacks to use before it evolves. Most importantly, Orbeetle is actually a really solid Pokemon, worth the effort of evolving Dottler.
3 Kirlia - 278 BST
For how prevalent Gardevoir is as a popular Pokemon, it's shocking just how bad Ralts and Kirlia are. Ralts is just terrible, having one of the lowest base stat totals in the whole series and originally couldn't be found with an attacking move. Kirlia isn't much better, and a trainer will spend a fair bit of time with Kirlia before its final stage.
Kirlia may have the solid typing of its final evolution, but it doesn't have the stats to back up any move it offers. Its best stat, its special attack, is a pathetic 65 base. It's also weak defensively, meaning a gentle breeze can knock it over. Luckily, the investment can net the trainer Gardevoir, one of the strongest fairy-types out there.
2 Spewpa - 213 BST
Sitting right above the bottom of the list is Spewpa, barely clearing the low bar set by its fellow bug-types. As the second-stage of Scatterbug, trainers only have to spend three levels training it before getting Vivillon. Vivillon, unfortuantely, isn't that great, but pretty much anything is better than Spewpa.
The best point of comparison for Spewpa are the other second-stage bug-types that are worse than it, but even there Spewpa still has a weakness. For some reason, it has less base HP than its fellow bug-types. It's a total mystery why Game Freak would do this, but it's a total mystery why they would intentionally make second-stage Pokemon this weak in the first place.
1 Metapod/Kakuna/Silcoon/Cascoon - 200 BST
Of course, the bottom of this list belongs to the usual suspects. Without looking, most trainers would likely make the assumption that these four would be at the bottom of the list, but it really is impressive just how bad they all are. They may evolve early, but that's no small comfort for bug-catchers looking to strike big.
To put into perspective how bad they are, the only baby Pokemon weaker than them is Azurill. Literal babies are running around with more power than these evolved Pokemon. They are in the bottom 20 Pokemon in terms of base stat totals in the whole series. Metapod and Kakuna have at least somewhat interesting evolutions to look forward to, but Silcoon and Cascoon don't even have that. These Pokemon are part of the reason bug Pokemon have a reputation of being weak.