I think the idea is that fuzzy search makes it easier for users to spot typos and this is a general feature of the flag library not something specific for --help.

Short-circuit any typo may be dangerous.

Now, an argument can be made for including as many aliases for "help" and "version" as possible but that's a different story

You can of course - I think the point here is it's different people with different goals writing the CLI lib vs the application.

So it's often not the case that a single person who made the decision to have a message that says "you asked for help, but you did it wrong; before I give you help you have to ask correctly."

"this dependency I picked at random from CPAN doesn't support that" is a pretty weak excuse for shipping a poor user experience

I don’t think people bother to write them, more likely it’s built in to whatever cli lib they happen to be using and they enable it.