This is a tired argument. SCSS was supposed to take over CSS... still waiting. For a hot minute, CoffeeScript was supposed to take over javascript. In the end, CoffeeScript didn't have a chance, but at the time many thought it did.
Typescript may be different and may be better, but there is a lot of rightly justified hesitation to adopting it.
As far as i know this was really never aim of the project. But everybody uses it. I would even say it oppened doors for JS compilation.. because everybody already has build process for css so why not js.
Typescript may be different and may be better, but there is a lot of rightly justified hesitation to adopting it.