It's just network effects. The real dirty secret of youtube is that it pays well relative to the other platforms, which ensures the vast majority of creators are on there, which in turn makes it the easiest platform to discover new content you like as a consumer and to be discovered as a new creator.

Privacy isn't the vector that is able to disrupt this (although it is a nice feature). This will get disrupted when some combination of the following tips the scales on a new platform enough to make the gulf in discovery small: - google screws with the search enough to make it hard to discover content users want (they are already 20% of the way to unusable at this point and getting worse every year),

- Someone makes an even worse for addiction platform that siphons the younger generation off who doesn't want to be on uncoool old guy's platform (i.e. what tiktok did to facebook/insta but also to some extent to youtube).

- Someone spends a crazy amount of money to pull creators off youtube onto their platform (nobody has spent enough money as diversely yet. spotify tried this half heartedly with rogan and twitch has tried it half heartedly with a few streamers but hasn't fixed their rev sharing so they are basically poison to everyone not big enough to get a sweetheart deal contract)