I used to keep my linkedin fresh just to see what feelers I get. I also funnel all recruiter emails into a folder. (It's a good ego boost sometimes, not gonna lie.) Last time I was looking for a job roughly four years ago, I just opened my email recruiter folder and started responding. Responded to four emails, (three faangs plus linkedin), and now I'm at a faang.

Now, there's no way to know for sure that keeping linkedin fresh actually helps. Also it was a special time where I had just finished an online masters in CS and I was really on a roll so I was taking a bunch of MOOCs afterwards as well. IMO keeping my linkedin updated with a degree in CS and mooc certificates helped. Normal day to day stuff I wouldn't update linkedin for.