there is symphony/laravel as web frameworks, which by all accounts are modern and highly usable, but that in itself doesn't distinguish php given how many alternatives exist
The major niche has been carved long ago. Low cost code for budget conscience clients. PHP has long been the easiest on-ramp to webdev for many folks and some of the things out of it Wordpress specifically, can be utilized to cover a vast number of rather low complexity needs. If you consult with budget conscience clients, you likely find PHP indispensable. If you (or your employer) are building your own software product, you care more about DX and such and have chosen something else. In both scenarios, the end users of the product do not give a damn what it was built with.