I've done some programming with typescript. IMHO the reason for around 50% of the javascript world now using it is that it provides substantial improvements over javascript that are real. Personally, I insist on typescript on any node.js or frontend javascript codebase these days.
Yes, it's not perfect. And, yes the inherent problems of javascript still leak through in many places. But with a little configuration, you can make the static code analyzer and compiler help you avoid most of that.
IMHO the amount of verbosity it adds is negligible. I actually measured a slight decrease in LOC when I was converting code. You add some type annotations (which IMHO also help human code readers) but then you also get access to syntactic sugar to offset that. It's a fair compromise considering that most tools trying to help the developer have more to go on and basically work much better. Ballpark your number of LOC is not going to grow when switching to typescript.
But IMHO it's just a gateway drug for developers to find their way to more capable languages. Personally, I'm interested in the direction that Jetbrains is taking with Kotlin-js, which with the next version will have some nice tooling around it to leverage typescript type definitions for integrating npms and hides most of the build tool madness behind gradle. The kotlin compiler has a much more sound/strict typesystem than typescript and also the language has quite a few language features that the typescript developers have not gotten around to supporting yet (they've been making progress catching up with recent releases though). They are also addressing size of the minified code. With the recent improvements, hello world is now a lot more reasonable than it used to be (<80kb instead of ~1MB). It eliminated unused code more effectively.
If you feel brave, you can get started with this on a modern react project right away. Most of the dependencies you'd use for that should just work fine with kotlin-js. But realistically it's probably going to take another few years to stabilize. IMHO Kotlin is interesting because it is already widely used by frontend developers on Android and has a lively ecosystem of frameworks that might also make sense in a browser. Also co-routines are nicer than async await in typescript.
And of course WASM is opening up this space further to just about any language. So for people finding themselves a taste for more/better typing, there will be plenty of alternatives for typescript.
Yes, it's not perfect. And, yes the inherent problems of javascript still leak through in many places. But with a little configuration, you can make the static code analyzer and compiler help you avoid most of that.
IMHO the amount of verbosity it adds is negligible. I actually measured a slight decrease in LOC when I was converting code. You add some type annotations (which IMHO also help human code readers) but then you also get access to syntactic sugar to offset that. It's a fair compromise considering that most tools trying to help the developer have more to go on and basically work much better. Ballpark your number of LOC is not going to grow when switching to typescript.
But IMHO it's just a gateway drug for developers to find their way to more capable languages. Personally, I'm interested in the direction that Jetbrains is taking with Kotlin-js, which with the next version will have some nice tooling around it to leverage typescript type definitions for integrating npms and hides most of the build tool madness behind gradle. The kotlin compiler has a much more sound/strict typesystem than typescript and also the language has quite a few language features that the typescript developers have not gotten around to supporting yet (they've been making progress catching up with recent releases though). They are also addressing size of the minified code. With the recent improvements, hello world is now a lot more reasonable than it used to be (<80kb instead of ~1MB). It eliminated unused code more effectively.
If you feel brave, you can get started with this on a modern react project right away. Most of the dependencies you'd use for that should just work fine with kotlin-js. But realistically it's probably going to take another few years to stabilize. IMHO Kotlin is interesting because it is already widely used by frontend developers on Android and has a lively ecosystem of frameworks that might also make sense in a browser. Also co-routines are nicer than async await in typescript.
And of course WASM is opening up this space further to just about any language. So for people finding themselves a taste for more/better typing, there will be plenty of alternatives for typescript.