My new Mac laptop in 2016 came installed with Python 2.7 from Apple. It's that kind of subtle defaults that I think slowed the transition. I didn't want to change the system Python.
In 2016, that laptop also came with System Integrity Protection - you couldn't change /usr/bin/python if you wanted to. And you still can't to this very day. Changing System-provided python was always against recommendations in prior OS versions because the next OS update could re-replace it at any time.
I agree that it probably contributed to python 2 inertia as it was re-exposing people to the idea that "typing python in the Terminal gets me python 2" and "I just used what I already had" - but it definitely wasn't stopping people installing a newer version.
Hopefully they will fix the shitty keyboard before that happens, so I can finally replace my old Macbook Pro.
Scripting Language Runtimes
Deprecations
Scripting language runtimes such as Python, Ruby, and Perl are included in macOS for compatibility with legacy software. Future versions of macOS won’t include scripting language runtimes by default, and might require you to install additional packages. If your software depends on scripting languages, it’s recommended that you bundle the runtime within the app. (49764202)
Use of Python 2.7 isn’t recommended as this version is included in macOS for compatibility with legacy software. Future versions of macOS won’t include Python 2.7.
