I wonder why it took you years to realize this. I'd never use a dynamically typed language for more than a few hundred lines of code, it becomes an unmaintainable mess afterwards. So serious question: Why?
We just also happen to really like JavaScript, feeling that it and the ecosystem around us makes us more productive given our needs. TypeScript a few years ago was simply not good enough, and neither were the alternatives.
It's okay if you feel otherwise, but trust that there are quite a few developers out there who are comfortable with building and maintaining rather large JavaScript codebases, building pretty impressive applications with it. This post isn't yet another "JavaScript is terrible" rant, I quite like it.
There are millions(trillions?) of lines of code out there that is maintainable and dynamically typed.
(I think this is because a lot of the advantages associated with dynamic typing were in fact portable back to statically typed languages. If you're comparing C++98 to Python, the dynamically typed language seems pretty nice. If you're comparing Javascript to Golang or TypeScript, not so much.)
There are a few valid arguments in favor of dynamic typing - but that isn't one of them.