Comment by skeledrew
Interestingly I recently had to run a script I wrote for 3.11 on an old system that has 3.6, and the only thing I had to remove were a few type hints (which of course don't affect function). Seems pretty backwards compatible to me.
Pretty compatible != compatible.
(I can edit my own script, I would hate if installation instructions for “django” would include “just remove the type hints from the scripts”)