> it isn't possible to statically know how much stack size would be required. It's not just that - if it were merely that you couldn't know the size statically

> it isn't possible to statically know how much stack size would be required. It's not just that - if it were merely that you couldn't know the size statically, you could use dynamic memory allocation. The problem with that though, is that now every (not provably nonrecursive) function call can now fail with a memory allocation error, and if your language doesn't surface that to the caller, and (correctly) doesn't allow spurious errors to appear out of nowhere (cough every modern programming language cough cough), there's no way to handle that error.