I always wonder why PHP never seems to favour making breaking changes to keep things cleaner, if you aren't going to improve language constructs in a major version, when will they be cleaned up?
PHP 8 has plenty of breaking changes (https://github.com/php/php-src/blob/08e6c209550a268500bbdef4...), mostly in the department of throwing errors more aggressively, and fixing some long-standing "features" (like 0 == "foobar" being true). But there's a budget to this, and you have to strike a balance between how much code you break and what benefit you get out it.
I think that post Python 3 nobody is going to do that.
It would be interesting to see a fork which removed all the crud though. Something that was easy to use for the person doing occaisional web work or beginner but without the traps and pitfalls.
Python 3 attempted too much change at once. The Python folks could have spread incremental rollout of the changes across several major version numbers and probably not have faced such slow adoption.
I'm not sure that they could have spread it out. I believe that was the point of Python 3. Still, PHP may end up in the exact same position Python was in for the last decade, if they tried to do a similar change.
It could be worse of cause, they could end up like Perl 6 (now Raku), which makes Python 3 look like a successful transition in comparison.