I use tiktok daily or every other day, I can provide some first hand anecdotes.

Dances are funny to me, at least the ones I see, they remind me of memes; it’s about 10% of my feed.

I have no idea what are icebergs (please explain).

Video responses (“duets” / “stitches”) can be funny or informative. Also perhaps 10%.

I‘ve seen “sludge” only in a simpler form (minecraft gameplay and an automated voice reading a reddit post), I saw it maybe 2-3 times total.

My point is just like you can tweak your twitter, reddit, etc experience to show you the content you want and enjoy - you can do the same with tiktok.

Although if you don’t like vertical videos then absolutely skip it.