Would be interesting to know, whether they purely optimize for the money and jumped ship at every opportunity, or they somehow managed to make recruiters pay attention to their profile and actually read and understand anything on the profile. And if so, how they managed to make recruiters do that.
I think it's just a matter of better odds with better discoverability. Also, every jump almost always entails a monotonic improvement in pay and likely also the title. And the tech job market seems to have been quite buyoant in the past couple of years.
Every time you update your LinkedIn page, recruiters throw themselves at you, matching your profile to whatever search keywords they have configured. Some of them turn out to be clueless, some of them turn out to have bad opportunities available, but some of them turn out to be surprisingly savvy and have access to good jobs.
I just recently got a new job that I think it's pretty good, and I didn't have to submit a single "blind" application. All of my interviews came through recruiters via Linkedin.
It's a relatively low effort way to have a steady flow of opportunities, one of which might turn out to be good once in a while.
