Yep, they are mostly similar but not exactly the same.

I developed a small web-based game and even that one required quite a bit of testing and debugging from players' reports as it seems every manufacturer uses a different default browser.

I have a check specifically for UC Browser (had no idea of its existence) as it has a bug regarding dates. Go figure.

And then people downvote me because they think all is Chrome and Firefox, while that's not the whole picture at all.