But that code won't work in five years, because all the distros will remove python3 in favour of python4. (also, the code from 5 years ago written for python 2.

But that code won't work in five years, because all the distros will remove python3 in favour of python4. (also, the code from 5 years ago written for python 2.x doesn't work now, becauses distros removed python2) Do you really want to rewrite all your stuff every 5 years?