What if YouTube just does the same, but the goal of the algorithm is not to maximize like/dislike ratios, but actual click-through rate and watch time? [1] It's an ad company after all. Also, the domain of TikTok videos seems very limited in comparison to YouTube videos, so your like-based algorithm might result in bad user retention with this broad strategy of showing random videos.

So the question really is: If YouTube's algorithm is more sophisticated than TikTok's and TikTok is trying to do the same, would they still be as transparent about it?

[1] https://youtu.be/fHsa9DqmId8?t=838