"with Python, the 2–3 change was a bit of a nightmare"
As someone who personally worked in an organization that dealt with Python, including while trying to deal with 2-3 change, it is/was more than a nightmare.
I was in a job interview just this week where my interviewer stated "you dealt with Python 2-3 phase? That's crazy, we're still dealing with it now". That was beyond the silly parens after a print statement.
Everything is so fast to change nowadays, nothing seems relevant. Perl 19, Python 86, C 4016, quarterly profits, not seeing long term, do what's coming out of 'college'... things seem to be speeding up to achieve the inevitability of futile.
Interesting watching it happen, it has been.