Is there any reason to keep steam and Windows store versions at same time?

are there any version specific events or anything (i think recall seeing it but not sure) where i'd benefit from keeping the other version installed?

Microsoft, Steam, and Epic all have unique rewards for logging in (and playing a little?) on them. If you already claimed those before, there is nothing new to claim AFAIK.

Beta reward, game pass ultimate perk and once in a blue moon Microsoft exclusives events