Arch Linux drops Python 2

That's overstating it quite a bit. If you have a complex Python codebase, it may need some maintenance to keep up with newer versions but how much and how often will vary depending on the features you use and the libraries you are relying on. Sometimes you do live in an ecosystem that is already heavily reliant on a language and there isn't much you can do about it but if you are starting new, I would recommend using alternatives like Go if the codebase is expected to live long and remain fairly untouched.