FC 25 Coins essentially lives and dies by its multiplayer scene, so the low player count is a concern. Sure, there will always be offline matches, but AI opponents are only interesting for so long. Those with friends to play with consistently shouldn't worry too much, but the vast majority of people looking to jump in for a match or two during the day will find it frustrating.
The bright side is that when FC 25 is running well on Stadia it's almost impossible to tell the difference between it and its console counterparts. Some matches went without any technical hiccups, and those were our highest scoring almost without fail. During those times, Stadia's promise of gaming driven by the cloud shines through, and it's truly a marvel to think that it's all running through a web browser. Unfortunately, it just can't hit that high note consistently enough to justify this version as the one to buy.
FC 25 itself, though, is a game worth picking up for fans of sports titles, though it certainly doesn't reinvent the wheel. For those that picked up FC 25. it may be worth it to wait and see what next year holds. It's a common criticism for the franchise, but it feels especially true this year, especially since there's not a real story mode to play through.
For those without a console, FC 25 on Stadia is still a better option than not being able to play whatsoever. But with consoles like the Xbox Series S being available without breaking the bank, it doesn't make a ton of sense to opt for the Stadia version once the cost of a Chromecast Ultra and compatible controller are factored in. Those that intend to play from a Chrome browser tab and already own a compatible controller have a better reason to pick it up through Stadia, but that's entirely situational.
Simply put, the convenience of launching FC 25 without downloading can't outweigh the technical issues presented by Stadia as a platform. It feels harsh to say that Stadia is the only thing holding the game back, but there's no other culprit to be found when the core problem is the constant barrage of network issues. The reality is that Stadia is struggling with something as formulaic as FC 25. and that's legitimately troubling. It's yet another story of the highest highs and the lowest lows, and it spells further problems for the buy FIFA Coins of the platform.