I was a tech recruiter before moving into eng work. I always preferred if someone I'd placed in the past or gotten a number of good interviews for reached out to me if they were looking but I never really expected it.

Even if they did it often depended on what I was working on at that moment. The might be the best backend rails engineer I've ever worked with but if I'm only working on front end react roles I'm not going to have anything for them.

Because I had relationships I could call past clients who I know needed good rails folks and pitch this persons background but they would open up a role maybe 25% of the time?

It's just difficult because third party recruiters don't really control the roles they work on.