For python code, yeah, most of it.
Python does sometimes have backwards-incompatible changes, e.g. for 3.10 they removed a bunch of stdlib modules and methods, like the "formatter" and "parser" module [0].
So if you used those, your code wouldn't work in 3.10.
But the main reason to wait for wheels (which is pythonese for "pre-built packages") is if they use native code (like C or rust) and you would have to compile them yourself otherwise, which increases installation time quite a bit.
(this was also the reason why Alpine was a bad choice for python containers for a long time because it uses musl and there were only wheels for glibc available. AFAIK musl wheels exist now so that isn't relevant anymore)