it happened all the time when almost all of the graphic designers (which were thrust into the roles of UI designers) were on mac and usually ios but got the task of "designing an app", which meant _one_ design for both ios and android. as an android developer i had to fight the OS, the framework and pretty much everything else to make the designers vision work, which resulted in buggy apps that felt unintuitive to use.
E.g. visit https://twitter.com/ and select Sign-up. I don't know what OS you are on, but the sign-up box probably doesn't look native. Users accept this. So what is the problem, really?
platform design choices are much more than the look of a button. it's choice and arrangement of ui elements, navigation systems, metaphors, ...
if you just see it as "button on windows" vs. "button on macos" it's not that obvious, but think about how you'd design an email client on windows vs. command line vs. mobile phone vs. smart watch.
a simple "button" might be roughly the same on every platform, but the overall design would be quite different.
Sorry, but the problems you are talking about are first-world problems imho. If the button looks like a button, and clicks like a button, what is the problem really?