The main problem is the environments we have to code in are garbage; the simplest solutions to complexity are often standardized at the language/environment level but implementations are years late.

There is more money in building products and coming up with workarounds than there is in improving the environments we all have to work with. There are also too few smart people in the world available to keep up with demand for both activities.

Instead of 10 people keeping IE up to date with modern JS language features, we had millions of people people trying to come up with and use genius solutions (Babel anyone?) to transpile and polyfill their code backwards. Instead of 4 people adding support for ES Modules to Node.js years ago, we have have many thousands of people trying to work out WTF to do on their own.

The solution is not to freeze technology in its currently deficient state and to be content, that attitude on behalf of environment maintainers is how we ended up here in the first place!

JS will be "mature" and infinitely more productive once basics like modules are implemented in all servers and clients. It will get better eventually.