[fredrik-j]

While CPython 3.x is rock solid and shipped years ago - no argument there - both Pypy and Jython still lacks stable Python 3.x releases. That's a major migration pain point.

It is hard trying to introduce Python 3 at a place that has systems that depend on both Cpython and Jython. Jumping between python 2 and 3 between projects is quite taxing mentally. And staying on python 2 only leaves me with a sense of lingering doom to say nothing of having to endure all the idiosyncrasies of python 2.x. I really enjoy the few moments when I can use Python 3.

It is perhaps easy to consider the 2 vs 3 debate over and done with for people who can just disregard Pypy and Jython entirely in their environment. I probably would think so myself had I not been so unfortunate to be the unwilling maintainer of solutions dependent on Jython right now.

[sigzero]

Jython has always been behind and sometimes by a large margin. I don't think that is a "major" migration point at all.