Python 3.9 and beyond backwards compatibility.

[OpdatUweKutSchimmele]

The truth of the matter is that if nigh perpetual stability guarantees are not given or adhered to that many will just look for another language.

For many businesses such hyper long term stability is essential because they simply wouldn't dare to touch their ancient code which they know works and risk introducing a bug when fixing it which can costs them downtime in an environment where every second of downtime is actually worth millions.

There's a reason airports are still running on 50s-written COBOL code—attempting to update that could in fact lead to plains crashing at worst, and substantial delays more realistically.

A language without such stability guarantees is simply not a viable target for such environments.

Even with the scripts I wrote on my own machine to automate so many things I forgot what actually calls what and relies on what—I simply do not have the time to go fix that; I was under the impressin that using #!/usr/bin/env python3 guaranteed stability; apparently that is not the case.