In my opinion, FIFA 20 is a very bad arcady "Soccer game", while not perfect, PES 20 (eFootball) is way better.
And also I hope the next port are optimized, I mean I returned too many games due to latency (Breakpoint, ACO, NBA 2k20)... While other game has absolutely 0 lag (The division 2, Gylt, Grid...)
PES on stadia would be a disaster due to it's already heavy gameplay (more input lag in a game engine where it already exists) and its unpopular compared to FIFA so would have to cross play with PC which is heavy on cheats especially with PES.
FIFA worst game but more popular and could easy cross play since its dedicated servers and way more smoother with reaction to input's.
Always played PES but honestly I'd rather have FIFA here.