One example where it's leaky is when you want to memoize something, and now you need to memoize all its dependencies, recursively, and you end up with a 30 file

One example where it's leaky is when you want to memoize something, and now you need to memoize all its dependencies, recursively, and you end up with a 30 file PR. I say this as a big fan of React, and I'm hoping the compiler turns out a success.