Personalised ads are beside the point. The issue is how they are personalised, namely by building a rich profile of user behaviour based on non-consensual tracking.
It isnt even clear that there's a meaningful sense of 'consent' to what modern ad companies (ie., google, facebook, amazon, increasingly microsoft, etc.) do. There is both an individual harm, but a massive collective arm, to the infrastructure of behavioural tracking that has been built by these companies.
This infrastructure should be, largely, illegal. The technology to end any form of privacy is presently deployed only for ads, but should not be deployed anywhere at all.
it's more than the ads. imagine if hacker news used ML to determine what articles you see on the front page based on whatever ad campaigns they think will result in a click from you. that would suck, right?
that's what these platforms do though, and that's not okay