I still write and actually still (sorta-kinda) like PHP, but there's no major concept/feature I can think of that's intrinsic to PHP rather than inherited from other languages. The Perl (and general "C-like language" influence is notable, and as PHP has matured it's started to feel ever more like Java. ("To write a simple PHP server app, first just initialize your PSR-11 compatible dependency injection container and add your PSR-7 compatible HTTP request/response handlers to it...")