I don't recall hearing any serious criticism claiming that it was hard to get things done with (unless you count security).
Manageable is subjective. There's no evidence that it's "just right" or even "timely". Major API cleanup would be appropriate for php 8 but there's still too many people clinging to the idea that PHP would be damaged because someone can't look up how to solve PHP problems with specific versions (ie are stuck in the late 90s).
There's so much that could be done in one fell swoop, the steering council of neckbeards (PHP neckbeards are as bad as it sounds) are responsible for the stunted development of the language. To suggest they are the progressive face of PHP is, at best, revisionist.
There's plenty of features in the docs that say at the top "deprecated in x, removed in y, see also alternative z", so I'm unsure of what problem you're referring to.
We ended up rewriting the entire product in Python.
I've done PHP for more than 10 years and got no problem using it if I have to.
OTOH, I don't want to touch stuff like rails because I don't like it being in the way but love Ruby.
I'd prefer TypeScript these days though.