10% useful for maintaining a contact list and just occasionally checking up on what former colleagues are up to.
5% Occasionally come across some useful or actually intriguing post that does give me some insight.
85% PR puffery or posts from grifters. If you see someone leading with “Top X LinkedIn” whatever, generally really best to run the other way quickly. Top folks never actually lead with that crap.
The truly most successful and knowledgeable folks typically only post on LinkedIn rarely or not at all. That leaves LinkedIn this odd pool of people trying to impress other people that mostly aren’t spending their time on LinkedIn.