>TikTok isn't really fundamentally different from the stuff we consider web2, is it?
Yes, it is. It's only superficially similar (technically "user-generated" content). It's a qualitative difference. The fundamental difference is human-curated vs algorithmic. You go on youtube or instagram or tiktok and all you see is what the algorithm pushes: usually the shittiest most junk content imaginable. It's a qualitative difference from having your blogs and following links and etc.
The other main difference is of course that it's now all commercial. Everything everywhere, be it a google search for "best blender" to a youtube frontpage, is trying to sell you stuff or to make you click on ads. It contaminates everything.