This would be like Starbucks randomly serving tea to 20% of customers who order coffee because they want to compete more effectively with Lipton. That’s not how competition works.
https://www.jimcollins.com/concepts/the-flywheel.html
and you might think, "I have (say) N=250,000 people playing game A and I can get them playing game B" you are probably going to be disappointed and very lucky if you get somewhere between 250 and 2500 of them playing your new game.
The two-sided market that makes YouTube impossible to dethrone makes it just as hard to change direction. For one thing you have to change the behavior of the viewers, but you also have to change the behavior of the creators, who know how to make videos, who know how to monetize them, all of that.
Myself I find I don't have a big attention span for short videos. I mean, Chinese girls doing the robot turn on my mirror neurons as much as anything. I can watch a 30 second video and get 30 seconds of fun but I don't want to watch another and another and another. However I cannot get enough of Techmoan talking about tape decks and such
The analogy fails as well. It would be more like Starbucks asking every customer whether they want tea as well. And I imagine that whichever tea company is partnered with Starbucks at that point is going to be very happy. Product bundling works very well, especially in cases like this, when an established giant decides that they are going now offer the thing as well. YouTube Music worked the same.