The reasons to upgrade are often dependent upon your usage case. To me, the Unicode improvements are reason enough on their own before you even get into the other great stuff (async work, type hinting, stdlib cleanup, pyc rework, etc).

asyncio is going to be a slow build, as the ecosystem starts unifying around it. But as that happens, we'll be much better off for it.

Ruby offered an immediate 25% performance increase. That's a lot less niche than Unicode.

LOL, "niche", says the english native.

Plus, 25% of performance, while nice, is not really something that would matter for most Ruby projects. They are web projects, and their bottleneck is not Ruby. Same for Python. While I'm telling you, good unicode support in most european countries is a HUGE deal.

But that's not all. Often People thinking about Python 3 think unicode, but for me there are 2 other things that made my life much nicer:

- better debugging. Error handling is a hell lot better, with better and messages, greater granularity, more safety nets... E.g: you can't compare some objects anymore, you have several exceptions to handle file opening, imports are absolute by default, division is what you expects, a lot more operations are lazy, the stdlib has been cleaned manu redundancies, encoding parameters everywhere, etc. - less verbosity. Writting is consistently reduced. You get finner file boilerplate, shortcuts for OO, unpacking generalization, yield from, f-strings, etc.

Now those are things that are not easy to sell. You don't see them as a reason to migrate when you hear about it. But once you used to them, going back to Python 2.7 feels so bad.

Unicode is niche?