The whole thing is ridiculous and weird and fear-based, honestly. It begins with the silly assumption that the consumer base is so reactionary and easily upset that the presence of black-bars will cause a significant number of viewers to balk and refuse to watch the programming. Which, so far as I know, has never been tested, and is completely untrue. Its only real precedent comes from when the decision was made in the early days of home video to bypass presenting movies in their original theatrical ratio for the sake of filling the screen on a tv, as not only were tvs square-shaped, but were significantly smaller, and were watched in most living rooms at a semi-fair distance. Which is again, not the case today, as even the cheap TVs are typically minimum 42" and the small screens, such as phones and tablets, are being watched much closer up, effectively replicaing the FOV you’d get at a theater.
And that’s not even getting into the fact most viewers are far more sophisticated about aspect ratios and why the black bars are there than they were in the '80s and 90s.
Basically - programmers and decisionmakers at most networks just assume their audiences are easily-upset rubes and babies unable to sit through the tiny acclimation period it takes to stop paying attention to the black bars - and they think the best way to solve the problem of their presumed-to-be-idiot audience is to placate the lowest common denominator at the expense of the movie and its creators. So instead of those “rubes” being reminded that if they’re honestly THAT upset about black bars they can hit the zoom button that comes for free on every remote of every TV sold in the last 10+ years, the solution is to chop up the movie before it’s presented. Because that’s how they’ve always done it, thanks to circumstances that basically don’t exist anymore, paired with circumstances that likely never existed back then, either.
There’s basically zero reason why every movie isn’t simply presented as it was intended to be seen by its director, as the default, and then the consumer can decide how they want to butcher it on their own if they’re that concerned about “not getting all the TV they paid for.”