Well, if it is abusive or not will be determined by the majority of people. If their numbers start going down because of this, they’ll act on it. If not, it means the majority of people are willing to see the ads to get to the content.
This is logical nonsense. If their numbers don't go down, that doesn't make their actions not abusive, it simply indicates that people are willing to put up with the abuse (because they get enough value out of the platform despite the abuse). Whether it is abusive or not is not a numbers game.
People also complained when YouTube implemented ads in the beginning, very short ones. Clearly, the majority of people were fine with it.
This means that people still derived enough value from the platform, despite the ads. That is, stopping using the platform would be more of a net loss than accepting ads on the platform. And yet, this doesn't have anything to do with whether it is an abusive practice or not.
In fact, you're touching on something here: ads were initially very brief and intermittent; they've gotten progressively worse and more invasive and so, just as boiling a frog, you can't take peoples' acceptance of the situation at face value. If you've conditioned someone to put up with (worsening) abuse, their seeming acceptance of the situation doesn't mean you aren't being abusive.