It's not as black and white as you claim. 99% is obviously much better than 0%, and 99.999% would be an exceptional, unheard-of improvement. In most software projects, this would find ALL bugs.

And most "memory safe" languages are not all that memory safe. Or they need escape hooks.

EDIT: To be clear it's not AT ALL black and white. You have drunken too much of the type safety kool-aid.