I don't think it's anything like the Python jump from 2 to 3. That changed the behavior of a lot of code (unicode vs bytes, various syntax changes, import chang

I don't think it's anything like the Python jump from 2 to 3. That changed the behavior of a lot of code (unicode vs bytes, various syntax changes, import changes, etc), and there was no way to automatically upgrade a codebase (2to3 didn't really work). With the addition of generics to Go, they've been careful to ensure it's fully backwards compatible, so all existing code will still work as is. Major version bumps are for incompatible changes (like Python 2.x to 3.x). What they're recommending with isolating generic code in existing libraries is so users of older versions of Go (1.17 and prior) can still use those libraries, just not any new functions/types the libraries have added that use generics, and hence require Go 1.18.