Well, it's pretty clear in this case. Typescript has even more traction and better integration (like VSCode's magical definition fetching) than I think anyone could have imagined. It dominated its reasonable competitor, Flow.
It's kind of a freak win. I think we can say confidently that nothing is going to usurp it.
Not like any compile-to-JS language has come close even when JS was at its worse. Now JS is so good I don't even know why I'd use another dynamically typed language.
We rarely get blindsided by what actually gets traction because almost nothing does. Something that looks like Typescript isn't going to beat Typescript. Something that's more foreign looking certainly isn't either.
