Most decision-makers make decisions based on what they already know. Most of my colleagues only know React, because they've only been exposed to React. Why do you think Java dominates the market still? React solved a huge problem when it was new, and it still solves that problem fine (change detection - the reactivity model). There are better alternatives available now (Vue - signals), but the difference isn't big enough to create a new monoculture. Sure there are peripheral concerns like how mature the ecosystem is or the particular ergonomics of a framework, but these are mostly fluff.