I actually find it pretty useful. I've used it to cold call people in different companies and functional roles just to pick their brains, people are surprisingly open to it.

Also, it's helpful as a contact database when a former colleague changes their email address/phone number.

The "request an intro" is pretty good to just to see how you're connected. If you know someone in common with a person it tends to lower the barrier of a cold call.

Note: by cold call I don't mean selling, just getting a chance to talk to someone interesting; i.e. you see an interesting role and want to get the real deal about a company