> I believe these are the exact technical advancement the top-level poster was contrasting with cable networks
You would have had to guess, because it went unspecified.
If we're talking about algorithms to surface content, we should talk about them; although I'm pretty sure that has nothing to do with cable television. Cable television advertised in the way we are told than advertising is not bad: they created specialized channels, and took advertisements on those channels that people who were interested in those specialty subjects would also be interested in. They didn't track or attempt to manipulate individuals.
I don't know what cable television did that was special or above and beyond what a magazine or a newspaper supplement 100 years ago would have done. The only difference between TV and magazines is that you don't consume TV, it's simply pointed in your direction - and you can't skip around ads. This is notably not true about modern television, though. If anything, it has technically fallen backwards since DVRs (or even videotape in general.)
I think a lot of intellectuals were forced to take Cambridge Analytics' marketing claims as truth because of the political positions they entrenched themselves in shortly after that scandal broke.
It's certainly caused a lot of 50s narratives about Vietnamese and Chinese communist mind control to come back posing as serious science, and a bunch of Key's "Subliminal Seduction"'s grotesque sexiness mixed in to make it nominally anticorporate. Although, predictably, it has generally been expressed politically as giving social media more ability or even responsibility to suppress the speech of average, un-notable citizens when they go against government narratives about controversial subjects.
That is not defeating social media, that is defining and institutionalizing social media as a trust and a means of government control. There is no reason we couldn't have had this same argument about telephones, other than that the average US citizen was less disdainful of their own civil rights back then - civics was drilled in as a religion, and it involved obligations the state had to you. Obligations that you are not allowed to give up if you want to live in a civilized, democratic country.
This was why we don't have government police whose job is to listen to random phone calls and periodically butt in to tell the speakers to change the subject, or arbitrarily cutting the line, collecting lists of people who need more intervention, or banning people from being able to use phones because they were seen at a political protest. If you ever wonder why the mails are so sacred, it's because the mail came about when people were prouder and had more shame than we have now.
If you want to regulate algorithms, regulate algorithms. Don't regulate "social media." If you have to argue about what it is, it is a useless term.