I use LinkedIn to passively trawl offers from recruiters and ask for references. Most offers aren't particularly good but a few random recruiting recruiting connections I made ended up being important. The data I give LinkedIn effectively matches my resume which I have to be comfortable to send to random people in the first place, so I'm not particularly worried about the data provided. I do not browse the feed or post anything publically. I only privately message people I'm connected with, or those who provided a job posting I was willing to apply to.

The more socially competent you are, the less useful this probably is. Many people probably have some useful network of friends they built in college. I have little to draw on aside from a handful of people I worked with which I had professional rapport with which I never developed a personal connection. So thus, I am stuck on LinkedIn on the off chance I need a new job and a reference.