Because people don't like using heavyweight solutions needlessly. That's the logic that begat C++ and Ada and Multics and ASN.1 and CORBA. All of which were good solutions useful for "everything" in their domain. But people hate them, mostly.
Historically big "everything" solutuions end up losing in the market to lighter weight paradigms with more agility and flexibility. Almost every time. React[1] was such a solution once!
[1] Which really is a shorthand for "modern node-based web development with tens of thousands of npm dependencies and thirteen separately-documented API and deployment environemnts to learn".