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.
I don't have anything against personalized ads based on information that I willingly share. If I am following a bunch of groups of kite-surfers, I actually welcome ads for kite-surfing gears and services while browsing those groups.
If I explicitly decide to share my address on my social network profile AND, explicitly authorize the use of this information for targeting, I don't mind, and actually welcome seeing ads for carpet cleaning services from my city, instead of ads from this kind of business located thousands of miles away, WHILE I am using said social network.
But I don't want to browse the local newspaper, and having this targeting information being used outside the explicitly bounded context of that social network.
And above all, I don't want surveillance-style stuff things forced upon me to infer information about me that I never consented to share in the first place.
It is ok to me if I say, I have an interest on X, you (and only you) can show me ads based on that, and I also consent on you (and only you) using my <insert whatever personal info you may think ok> to target ads.
When I visit facebooks https://www.facebook.com/off_facebook_activity I see that lots of places have shared my information with facebook..