[awesome_dude]

I mean - you're arguing there about a small blast radius, and I genuinely appreciate that not taking down the whole system when a bug occurs is incredibly valueable.

But, the discussion is about dynamic typing, and the fact that the function is in a state where it cannot compute because of bad input.

This might as well be a Null Pointer Exception - the function has encountered bad input, and crashes.

The argument is, that a MUCH stronger position is for all callers to be forced to provide input that cannot get the function into such a state - and a major subset of the set of all inputs possible can be eliminated with static or strict typing (I know the nomenclature gets a bit hazy here, but I hope that my intended meaning is clear)

If the callers know in advance that they cannot provide input shaped in ways that the function will not handle, then they will not call the function in those ways.

And that forces the call chain to be sure about the data transferred from top to bottom.