> obvious things

Obvious things may not look obvious from other programmers or for yourself sometime in the future or from a code you'd written while feeling asleep.

If you'd totally think that's an obvious overhead, just give it "any". Though I never use it.

Automatic type mismatch warning and auto completion in the editor feels quite worth the little "documentation" static typing effort.

Of course, if anyone is using some basic editors that don't even highlight TS errors in real time, then it feels like a complete waste of time.