I definitely won't go as far as those TypeScript absolutists who refuse to use any package that doesn't come with TS definitions, but surely TypeScript has become a solid staple in my day-to-day job as a tool that alleviates my cognitive load.
It's true that IDEs nowadays can figure out a lot of stuff on their own from plain JavaScript, but TypeScript allows them to run a nice extra mile.
There's also a discussion inside the W3C about replacing IDL with TypeScript when writing specs.