Fwiw, I still get recruiter emails now and then years after having shut off my LinkedIn account. If they mention how they found me, it's usually through GitHub.

...not that I've ever had anything useful come from talking to a recruiter. The useful bits have always come through my existing personal network more directly, or through meatspace networking. I shut down my LinkedIn because I basically started to view recruiter emails as spam.

Perhaps you are a dev, then GitHub/Lab is a good place to search for something specific, if your recruiter knows what the they exactly seek. In my line of work (audit/sec/GRC) most of my contracts start as "6 months of THIS" and they end 2-3 years later after I have worked on their operational model, on the manner their control framework is defined and executed, their deliveries to their external auditor are defined and scripted, and some more process-control-audit related parts are etched in stone (oh and some SOX 404 just because I was in the neighborhood)..

So in my world, having a CV with the necessary keywords (SOX, HIPAA, GDPR, COBIT, NIST SP 800/XX/yy/zz, NIST CSF, etc.) is a life saver because I always have headhunters calling me. I don't see them as spam. I just tell them to ring me 30 days before my contract/extension ends, and they gladly do so, and I stay working like this.

I don't spend more than 10minutes per month, and only to accept/ignore/reply to messages. I use it. I don't let it use me (apart from the fact that they sell my data to anyone who is willing to pay them).

Even as a dev I think the person you're replying to is wrong.

Sure - if you know people that work at the specific company you're interested in then you can just get a referral through them, but if you don't then having a history of email contact with recruiters at interesting companies via linked in is quite valuable and makes it easy to jump to the interview process.

The job market is strong so we (devs) get a lot of email from recruiters trying to hire, and the recruiter quality can vary (generally employees of the specific company are better than hired firms), but in general I think this is a good problem to have.

I don't categorize the person you're replying to this way, but I've definitely seen devs go on a bit of an ego trip because of the recruiter emails they get and then treat them dismissively. A career is long, there's no reason to be nasty to them or cut them off - at some point you might need their help.