Yes, we will never be able to prove that a program is 100% correct but that doesn't mean we shouldn't prefer solutions that bring that number up (statically typed languages) over solutions that don't (dynamically typed languages).
Just because you can't do something perfectly doesn't mean you shouldn't try to do it as best you can.
In the real world, it may well be the case that while you're screwing around with a baroque type system, your competition has iterated three or four times and your milkshake has been drunk.
Of course your compiler will never be able to proof the correctness (or lack of it) of all programs.
The relevant question is, what share of useful programs can our compilers help us creating? This is not answered yet, and you seem to have never even thought about it.