This is only partially true. For example, with React Native even the core team now tells you to "just use Expo", as if relegating all responsibility to a project maintained by a for-profit that thinks 2 weeks is enough time to beta test a Major release.

It's also dismissive of market forces, i.e. developers have to pay bills and therefore are easier to hire if they know the skillset that is in wide use.

I've never worked or interviewed a single senior that wanted to use Next.