JS's uses have been growing steadily. The language was clearly not "designed" (I saw a talk about the first 10d of JS, little actual designing happened).

TS is to the rescue when you have a big JS project, because that's what JS is not good at: big projects and large teams.

Except big JS projects with large teams existed well before Typescript ever did, and it never stopped anyone from producing good results. Typescript really isn't making anything possible that wasn't possible before Typescript existed.

I’d love a link to this talk if you happen to have it handy!