Why exactly typescript?

Typescript should be compileable into WebAssembly bytecodes and that's it.

If you want it to be transparently compileable, like foo.ts to be sent as WA bytecodes then something like mod-typescript (on the fly typescript compiler) can be designed that will send (compiled and cached) bytecodes.

I kinda dislike dealing with the configuration too but it's there for a reason; because one size doesn't fit all. Then again, it's not a major pain point for me as long as I stick to the defaults.

And deferring the transpiling to the browser won't really accomplish much, except increase load time for all users.

I'm currently working on a project with ~500KLOC of typescript, and transpiling it takes about 15 seconds on my devbox. It's still a bit too slow for my taste but I don't think there is a technical quick fix for this kind of stuff, rather it's a tale about a project which started small, organically grew larger over time, and would in many ways benefit from a clearer structure with clear dependencies.