Python 2 -> 3 change really was painful for Python community, but PHP does these almost fundamental breaking changes so often, that maybe people just get used to it? I haven't really followed Python past version 2, but I think they are less likely to ever do such amount of breaking changes.
There must be a lot of unmaintained PHP codebases that will break if PHP is updated by hosting provider etc. Someone must be pulling a lot of hairs because of this.
Edit: Those dogpiling there, I rest my case with josefresco's comment:
https://news.ycombinator.com/item?id=33907628
It's painful. Dropping dynamic properties? That will be a lot of fun. WordPress is probably biggest segment for PHP usage.
PHP has gone through a few changes.
PHP 3->4 was a moderately big change under the hood, and introduced a lot of new things, but most 3 'worked' under 4 (but was... awkward).
PHP 4->5 - a few 'big' things changed - XML processing changed - I had to use some shims to get some projects upgraded.
PHP 5->7 - my recollection, and that of most colleagues, is that this was pretty painless for most projects. I can't recall too many major breaking changes, but it was mostly just getting a doubling of speed without any substantive changes.
The PHP community has a couple decades of 'major version changes' to look at to learn from. I still can't say I agree with 100% of the decisions, but it's still progressing nicely.
More than a LTS release I'd prefer more PHP 8 releases than the five in 7.x, e.g. more until 8.8 or 8.9.