A significant percentage of my LinkedIn contacts are friends, ex-classmates, social acquaintances, other people who aren't in my "professional network" but I accepted their connection request because meh, why not? The fakeness is particularly obvious when reading their posts. I'm like "C'mon Dave, I know you don't really give a shit about car insurance, it's just a job. Do you talk this with your colleagues?"
I keep LinkedIn around because it's helped me find jobs in the past, but my experience on the site improved dramatically when I set up a custom uBlock Origin filter to hide the homepage news feed. I've never seen anything on there that remotely felt worth reading, and my most common reaction to other people's LinkedIn posts is to cringe.
Instagram has people posting “accidental” selfies that took 3 hours of make up, 156 tries under a full lighting rig and then an hour of post processing.
LinkedIn is full of that same brand of fake, just applied to work. Acting like some boring-ass conference was awesome, pretending that celebrating some minor work achievement with cake was the ultimate team building exercise etc.