My own experience is the streamers are promoting the hell out of their vapid reality shows. The only thing more pervasive are the true crime shows, but I have someone in my family who watches those, so at least it makes sense to see those in the “you might like” listings.
My mother in law watches the Jeopardy/Wheel hour which airs locally on ABC. Ss a result, I know first hour of ABC prime time is typically either a game show or a reality show.
I’ve spent most of this summer rewatching Babylon 5, John Wayne westerns, and Parks and Rec, yet the algorithm never recommends scifi, westerns, or sitcoms for me.