TV economics are hard. I think where basic cable and network TV make it work is that the content was filmed in a way to have natural ad breaks to make it less disruptive to the viewing experience. That becomes terrible when you shoehorn ads into places they don't belong. On the other hand, watching that content without ad breaks that was filmed with ad breaks also plays out weird because you'll have that commercial cliffhaner music/scene that is quickly followed with resolution before you have time to wonder "what is going to happen?" So shit gets weird when you have a tier model where some people get ad breaks and others don't because your content isn't made to satisfy both use cases.
TV is expensive to make and these are businesses that make money. A simple reductive "if user pays any money they deserve no ads" problem. It's a challenge of things like "The business needs to make X dollars per user and if we have ads we need to charge Y bucks where Y = X - expected ad revenue." The other challenge is in order to have an ad business you need to convince advertisers you have ad viewers they want to reach. Well, advertisers like rich people with lots of money, and they probably don't have the cheaper ad supported tiers. So can a TV company really support a completely ad free tier? Or do they still need to serve some, but less ads, to make sure their advertisers know they can get their ads seen by the platforms richest users?