I like what you’re saying, but wonder if we made small incompatible changes over time, would that solve the problem? For example (and please forgive me on this), but there are so many similarities between Python and different languages. Objects are obviously everywhere - C++, Java, .Net, etc; and syntax’s are similar at a cursory glance to things like Fortran. All of the above are much faster.
We took a decade to go from Python 2 to 3, but that had some pretty big changes. Going from 3 to 4 and getting a 50% speedup while making some (hopefully small) incompatible changes would probably be a good motivator for people to migrate faster.
There are obviously pros and cons to this discussion, but i really believe that stagnation is the worst choice. (Ok, Perl made a worse choice, but I’m presuming we learned that the level of change from 2-3 is as far as we can go in a generational update (x.0) ).