Well, he's using try/catch locally. You're not supposed to handle errors locally with exceptions. The whole point is inversion of control, you manage them at the point where you can do meaningful recovery, which then triggers the cleanup of the whole stack of frames once the exception bubbles up, rather than systematically cleaning up on the normal control flow path.

Regardless, in his example, he could achieve what he wants by wrapping the try in a lambda, and returning either the value from try or nullopt from catch. But clearly, that's just converting exceptions to another error-handling mechanism because he isn't doing it right.

He claimed that not handling an exception causes the program to crash, that's just plain incorrect. To be fair many people use the term "crash" liberally.

std::expected or equivalent is often used with std::error_code, which is an extensible system (error codes are arranged in categories) that among others interops with errno.