Xbox Game Pass is possibly the best subscription service currently available for games, with a massive library and access to many games on both Xbox and PC. The library only continues to expand with Microsoft's acquisition of Bethesda, but far more than just Xbox exclusives are available through the service. However, while Xbox Game Pass may be a model for other major game companies to emulate, it is not free of issues. One of its primary problems lies in expanding the service across platforms, to Windows as well as Xbox consoles.
One of the main draws of Xbox Game Pass is that it allows players to share their subscription across multiple different types of devices linked to their account. For those who own both a PC and an Xbox, they could, for example, use just one subscription to play FPS games on their computer and RPGs on their console. At the same time, it means that Microsoft can still sell subscriptions to people who have a PC and don't plan to get an Xbox, and vice-versa. This all sounds great, but out of the 530 total games currently on Game Pass, 373 can be accessed on console, and only 250 can be accessed from PC.
There is significant overlap, with many titles available on both, but it is also clear that PC-only subscribers have access to far fewer games than console-only subscribers for the same amount of money. Game Pass Ultimate subscribers get access to an expanded library that includes both PC and console games plus EA titles, but if they own just a PC and no console, they are still getting less content than their Xbox-owning peers. While it might seem like a minor complaint about what is otherwise a stellar service, there's no doubt that Microsoft should do something to make this situation as fair as possible.
There are only a few realistic ways that Microsoft can solve this issue. It's not as simple as just making sure all the games on Game Pass are available on both console and PC, since some titles are developed specifically for one and not the other, and Microsoft cannot force developers to make ports if they don't want to. While the number of games that are Xbox only or PC only will almost certainly shrink, there will always be some that cannot be made to work on both.
Likewise, making sure that the same total number of games is available on both ends of the subscription runs into issues as well. Just because the same number of games is available wouldn't mean that those games are worth the same amount. And, if one platform can get access to more titles, Microsoft shouldn't limit players' options just because it wouldn't be fair to people on another platform. This essentially means that the only viable solutions are charging PC subscribers less, or finding more creative ways to even out the benefits.
In the short term, charging Game Pass subscribers on PC slightly less than Xbox subscribers makes the most sense. Maybe when the number of games available to each platform is more equal, the price would go back up, but currently PC players are paying the same amount for access to roughly 120 fewer games, or a library about 33% smaller than what players on console get access to. Paying full price for 2/3 the content just isn't fair, but if the PC subscriptions was $6.99 to the Xbox's $9.99 it would be a much better deal.
That doesn't solve the issue for PC-only Game Pass Ultimate subscribers, but they are choosing to pay more for a premium version of the service that includes both game libraries, so they would likely largely be fine without an extra discount. Even so, getting a few bucks off the Ultimate subscription price as long as console-only games aren't accessed would be nice for those without an Xbox.
It might seem far-fetched, but there is one more possible solution to the difference in subscription prices, and it comes from game streaming. Microsoft is already experimenting with streaming certain cloud-enabled games to mobile devices for those with a Game Pass subscription. If PC players could stream console-only games to their computers and vice versa, the whole issue of different subscription pricing might be null and void. As we've seen with Stadia, it'll be a while before cloud-streaming games is perfect, but it won't be long before it's good enough.
As Microsoft's own head of cloud gaming assured Game Rant, the role of cloud services in Microsoft's gaming business will only continue to expand and improve. Part of that expansion may well be a narrowing of the gap between different platforms, enabled by streaming. With Game Pass, Microsoft was already pushing to erase the differences between console and PC, so the current state of the service may just be the first step in that process. For the time being though, Microsoft needs to make sure that players on PC are getting their money's worth, and currently that's simply not the case.