There are new frameworks all the time, but only very few establish a community that allows the framework to survive on the longer term. When you choose something that has been around for a long time, the probability for this is much higher, than for something that looks promising. Another benefit of the established frameworks is the amount of experience from various corner cases that has been coded in them. New frameworks often appear to handle simple use cases more conveniently, but that is only because they ignore all the complexity that the established solution has painfully learned throughout the years. You get that "for free" when you choose such a framework.