Nothing "wrong" with PHP itself, but it's clearly not designed for modern web programming patterns which makes it feel outdated. No separation of model-view-controller, not friendly for API or AJAX, no class structure until later add-on, and so on.
That's because PHP, like Ruby, Python and Javascript, is not an MVC framework. If you want that you have Laravel and Symfony. PHP, Laravel and Symfony are perfectly fine for returning JSON instead of HTML. I don't get your point. As for classes PHP has had them for 16 years.
