How Typescript saved me hours of debugging webpack
medium.com
medium.com
JavaScript developers weren't aware of what adding static typing could bring them and there was so much other stuff happening. Also, because JavaScript grew substantially in these years, many new devs joined and they had enough to do with learning JS.
Then CoffeeScript and later ES2015 came.
Many statically typed languages are able to compile to JS: Scala, Nim, Rust, Kotlin, Clojoure, Dart, OCaml/Reason.
Facebook even tries to add typing directly into JavaScript with Flow, which can even work with comments, so you aren't forced to run it through a special compiler before bundling.
It's a decent amount of cruft that you need to put in and it's not always smooth sailing.
TypeScript sometimes needs hinting and if you're doing it server-side. I once had to fix something in my node_modules because they were doing something wrong and TypeScript wouldn't compile unless I fixed that too.
I'm not saying that it's not worth it.
However, my team were severely turned off when we first started running with this.