I've interviewed so many junior and mid-level candidates who will opine at length about react vs. angular or why redux is the one true way to manage state, but who don't know about `setTimeout` or other fundamental language features. that kind of spotty, "just throw it together" knowledge may be enough to land a job somewhere, but it certainly isn't enough to solve anything beyond factory-floor, Lego-like app delivery.
I wish I knew the solution, because the problem only seems to be getting worse despite my thinking that "peak framework" is just around the corner in the js community.
It's hard to do a compromise when needing to know other parts of the stack (backend, DS, devops). Perhaps in several scenarios one can be happy with some Lego-like apps (pareto rule) and hire specialised frontend devs when needed?