I don't think the algorithm is that good, it's simply that the content is better.
I used TikTok for a couple of weeks and the product is very good. I uninstalled it not because I didn't like it but because I think it's another step in the wrong direction, for society and for me personally.
I believe the amazing content and algorithm go hand in hand. It isn't like humanity suddenly became more creative in 2019. TikTok has two things going for it that I believe create a feedback loop.
First, their algorithm is good. Those same memes and ideas are on reddit, YouTube and even Facebook but often they are buried. TikTok algorithm manages to surface them extremely well, finding the right audience for the content with a much higher degree of success.
Second, the low barrier to entry for creating new content means that ideas iterate more quickly. If I see a funny YouTube video and I have an idea on how to expand or refine the idea, it is a bit of effort to create the content. By contrast, the extremely low production bar on TikTok means people can riff on ideas in near real-time. What starts off as an amusing seed of an idea can grow into a mind-blowing work of comedy genius over the course of thousands of videos within a week.
At each step these work together - good idea is surfaced by the algo, hundreds of works inspired by it get created, the best of those ideas are surfaced, hundreds of works are derived.
However, I agree with you in the direction of "but for what?" Amusing Ourselves to Death [1] was written in 1985 and is as relevant as ever.
This is because the TikTok app has a very good toolset for creating the content. For YouTubers, creating a content means hours of filming and days of editing because high production requires that and AFAIK YouTube leaves all the implementation details to you. Many YouTubers have Hollywood level production workflow.
On the TikTok app you have all the means to edit the video on the spot. It's not Hollywood level production but it is still good. When TikTokers do something with high grade production, it feels off.
I used TikTok for a couple of weeks and the product is very good. I uninstalled it not because I didn't like it but because I think it's another step in the wrong direction, for society and for me personally.