Thanks for your question.

I see food preparation and dining rooms as separate industries, even if they don't appear that way at first. The most we can see this in practice is probably mall food courts. Web content like YouTube is the food and the web browser is the place or mechanism by which we consume "food".

Is being allowed to take tacos into McDonald's a hill I'm going to die on? No, of course not, it's just the first illustration I thought of. Lol. I could probably come up with a better example, that one was just easier and more visual.

To be clear, I'm not saying there's no anticompetitiveness happening, I'm saying that all vertical integration is basically this same amount of anticompetitiveness, and vertical integration is often very good, which is why we tolerate it all the time.

I agree the comparison to MS and Internet Explorer is somewhat similar. I also think that case was not decided particularly well, and it's not as revealing as it could have been since it ended up settling out of court, and IE ended up getting crushed by Chrome just a few years later.

I wonder, if Google made a new app called YouTube that could only watch YouTube and made it the only app that could watch YouTube, sort of like Quibi, would that be more competitive or less competitive? No one is asserting that Quibi was anticompetitive at all, correct? That would be even worse for Firefox users, they'd completely lose access to YouTube unless they downloaded a 2nd app, this time YouTube instead of Chrome, but like Quibi it would seem to dodge all these competition concerns completely. I think that shows how these concerns can be selective and kind of nonsensical.