In my PHP example, I was referring to programming frameworks in general. Not just front-end ones. Many apps have moved away from PHP as developers recognized its weak abstractions which lead to higher maintenance costs. For front-end, you can simply replace PHP with Java pagelets or jQuery soup.

You can write the same web app (from the user point of view) using Python, Ruby or PHP (frontend: jquery, backbone, angular). I do not disagree with this. However, the choice of frameworks is still very important and will determine your speed of development and any future maintenance.

Saying frameworks are irrelevant since they have the potential to all lead to the same outcomes seems a bit much. Any turing complete language can implement program as another turing complete language, but why do we have assembly vs Java vs C vs Python? Higher level programming languages and frameworks are for the human brain. It turns out the the human brain grasps some concepts better than other concepts: we call the more intuitive concepts abstraction.