But if you encrypt it so nobody else can read it then the big bad companies of evil will still need to collect your data individually - which brings us back to the initial point, but now with a blockchain for some reason

Companies are going to collect our data as long as they are able to use that data as an income stream.

I don’t have a Facebook account but I know they have data on me.

Yeah, and even if they can't sell collected data because we all agreed to just put them on a blockchain aggregates and whatnot will still be valuable assets. This isn't an issue that can be solved by technology. It will need regulation/laws and I don't see that happening.

But it’s different! Because blockchain!! /s