Here's one of the things that honestly surprised me about the Python 2 -> 3 debacle. I witnessed people in 2020 starting new Python projects and deliberately choosing Python 2. For no real reason. They were fully aware that Python 3 existed, but they just sort of arbitrarily chose to use Python 2. This was about 12 years after Python 3 was originally released, it was after Python 2 was sunset, and none of the dependencies of these projects required Python 2.

It honestly makes me feel a little nihilistic about versioning and upgrades. I know there were many legitimate technical challenges for many people in moving from Python 2 to 3. But I now feel that versioning is always going to be bumpy, regardless of the technical issues, because a substantial number of users will make strange decisions.