True, you absolutely can. They'll potentially make much less money, and I don't know that that's sustainable but I think it's at least an alternative worth talking about.
I think the other question would be "can you do tracking without violating privacy". To me, "<random user id likes cars>" is not a privacy violation.
Wordpress was founded, and hosted-Wordpress services ran for years, in an era where there was only non-personalized advertising. Why do you feel it would be unsustainable? As long as you limit media storage space and plugins, simple blogs cost extremely little to host per user.
I didn't say it's not sustainable, I'm saying it's potentially not sustainable. Sustainability of tracking-free ads would be a good conversation to have.
I believe it can be pretty good. I go to goodreads to track new releases and yeah, I wouldn’t mind ads if it were non invasive. Everyone that goes to goodreads is interested in reading and books in some form, so why not show ads about books here, instead of when I’m looking for music gear?
Newspapers ran for decades without any tracking, and they had to make and distribute physical objects.
Ah yes, print media, a thriving business.
You can even host them on your own server, and vet them for quality and security.