Most of them are merely abstraction layers for capabilities the browsers already provide. Rarely do they offer anything more. The big selling point is that they help organize the logic in a declarative way or automate a bunch of tiresome tasks that wouldn’t be there in the first place had you not used a mountain of tooling.

There are only 2 APIs in the browser: DOM and the web APIs. As far as writing cohesive logic that does wonderful things that’s on you. Most JS developers would rather it not be on them and instead adopt an Invented Here Syndrome mentality. The fear of writing any original code is very real.

https://en.m.wikipedia.org/wiki/Invented_here