* "I'll go with Angular since it's supported by Google"
* "When I'm not sure which library to use, I just choose the one with the most commits"
* "I'll just choose something with the most features in case I need them"
The upshot is that incremental, monolithic solutions get selected over and over because they're easiest to digest and usually supported by a well-known entity with lots of capital (lol meritocracy).
Ultimately, OSS is a poor vehicle for R&D because the market is every bit as dysfunctional and short-term-gain-seeking as the real market. Very strange.