I assume it is some inferiority complex, on many sides. PHP itself was laughed at being too simple, underpowered and inconsistent, now they overcorrected with types, annotations and breaking backwards compatibility with every release so that no old code base can remain intact. Frontend devs yearned to be regarded as real developers, which in their context means construction of unwieldly and overcomplex enterprise bullshit, thus typescript etc. And in the backend you have that same mechanism, devs having to prove they are no beginners and thus using (wrongly) design patterns, instructed by software architects, instead of avoiding abstraction and thus complexity.

No, I'm not bitter.