PHP has some benefits to its design that the vast majority of other languages don’t — deployment is as simple as “stick a .php file on in your website folder”, hitting the “refresh” button gets you the latest code with no “build” or “restart server” step, it’s all stateless shared-nothing so you won’t have data from one request changing the behaviour of another request, etc.
But the implementation has a lot of drawbacks - the language is painful, typing is bolted-on and still incomplete after years of work (eg there are no typed arrays), the standard library is an inconsistent mess thanks to its origins of “take several other language’s standard libraries and duct-tape them together”, etc.
“PHP-like but incompatible” isn’t in itself a useful feature — it is the thing which unlocks a bunch of useful features (a sensible standard library, sensible list/dict datatypes, typed collections, XHP, async functions, generics)
I have a hard time understanding the benefit of using a language that’s almost like a very popular one, but not quite.