PHP grew "organically" out of a perl library. There was never a consistent plan/idea about the set of abstractions it provides, the type system, builtin functions etc.. Everything has been bolted on here and there, some additions good, some bad, some terrible pitfalls. A language with builtin operators that are basically unusable (comparison!) and where some functions return false when the input is invalid, is really fundamentally broken. I agree that many of the worst failures of PHP have been (kind of) fixed after PHP5 and that's nice for large existing PHP codebases (mediawiki, wordpress, nextcloud, typo3). But I just can't understand why one would start new projects in PHP in a world where so many very well designed and well thought through languages exist.

Edit: First sentence is misleading. Of course it wasn't a perl lib, but basically a thrown together bunch of functionality, unified into one package, so it can replace using various perl libraries. The syntax was also very inspired by perl.