[Lazare]

> Is there anything that PHP is developing or adopting that can not be had at other established languages?

I would say no, but of course, the same is true of most other established languages. What's interesting about PHP is that it's shifting from being a dumpster fire that you would never pick over a real language like Python/Ruby/node/Java/whatever, to one that's honestly broadly comparable for many tasks.

Is it innovating or doing anything really unique? Well, no, but you don't tend to find much innovation or unique features in any of those languages (these days, anyhow). At best they copy them (eventually) from the innovative languages. :)

> I seriously would like to know if it makes sense for a non-PHP developer to look into it

No more or less so than any other big, mainstream, relatively popular language. Learn it because you need it for a job, or because you'd like to see how another language ecosystem solves common problems. Don't learn it thinking you're going to see anything especially new.