Well my logic for flutter is it's made by google, so it's support for android & google chrome will always be far better. Supposedly flutter is basically google's next gen UI toolkit for fuscia, so it will probably stick around.

Nobody focuses on windows or linux desktop, so it will be decent enough for them too. Google effectively owns the browser with chrome and flutter and chrome both use skia as their render system, so the likelihood of long standing bugs between them are reduced further.

Apple doesn't like it when their biggest direct competitor tries to commoditize them, and are not a money maker like games, so they foot drag in subtle ways to make flutter not as good of a thing.

I use iOS personally, so there is also a built in skill component there.

If the company got really big, then I would probably do a native web UI because web developers are easy to hire relative to many other types.