And Python 2 has run for 18, if we're counting by major versions. Heck, as long as you're okay with little changes like booleans not looking like integers anymore, you can run your Python 1 code 24 years later.
But imagine if Python followed the example of Perl. Python 3 becomes a curious side project, everyone moves back to Python 2, which goes on for decades without new features. At last, Python can have all the popularity and relevance of... Perl 5?
Python 2 will not stop running in 2020. No bomb is gonna explode. The dozen of volunteers will just stop providing free work for bug fix and security update.
But imagine if Python followed the example of Perl. Python 3 becomes a curious side project, everyone moves back to Python 2, which goes on for decades without new features. At last, Python can have all the popularity and relevance of... Perl 5?