For instance, if you have Paramount+, you can watch sports broadcast by your local CBS station through it. That station is going to be running commercials, Paramount+ has no input on it. The most they can do is run ads over their ads.
I'm assuming there's something similar with Disney+. You can watch your local ABC broadcast or ESPN broadcast of a game, but you're just getting that broadcast as being currently aired.
But even for broadcasts wholly owned and controlled by a streaming platform, like Thursday Night Football on Prime, there are just times when it would be dead air. I don't entirely mind commercials in that instance. Nothing else is going on.