No... You should learn the most popular frameworks. Why just react? Build the same project with svelte, Vue, angular. You'll learn a lot which applies across any web framework, that's more important.
If you're messing around and having fun, sure learn some hipster frameworks.
If you want to have highly saught -after skills years from now, basic web Dev with most popular frameworks on top is by far the safest bet.
You should at least google (or ask chat GPT?) about Lit before calling it some hipster framework. Lit is the old Polymer.js and being under development for the past 10 years. Still small, still making the best use of web standards.
I agree with you about knowing a bit of most popular frameworks tho, they are quite interchangeable and very often adopt each others famous features. The biggest advantage of choosing Lit as your main tool is that it is the one that is more integrated with web components that won't go anywhere, anytime.
I know what lit is, a former colleague tried to pitch my manager on migrating to it because he too loved web components and we were investigating microfrontends.
Turns out, it's quite trivial to publish react and angular components as web compenents.
That completely took the value prop away from lit, and in terms of DX and library support, the other frameworks won easily
I'm not saying don't use smaller frameworks. I'm saying the safest future bet is learning the big ones
If you're messing around and having fun, sure learn some hipster frameworks.
If you want to have highly saught -after skills years from now, basic web Dev with most popular frameworks on top is by far the safest bet.