I've actually gotten my current job and just received an offer from a FAANG due to LinkedIn cold calls. I can't speak to dark patterns, but saying the service has no value is disingenuous.
My first job was through recruiter page but my current job I got through a recruiter contacting me on LinkedIn. He even bumped my salary up by 15% from initial offer (because his cut was based on the salary and I also had another offer on the table).
It is a pretty valuable tool for a person moving countries for sure. Although I'm in Asia atm, I even got connected to a startup in SV while I were looking for jobs.