I hope proposals like this are eventually accepted.
I think it's safe to assume that we are trending towards: people caring more about privacy, browser fingerprinting getting harder, VPNs being standard (e.g. thanks to Apple), and third party cookies for tracking are either prevented by major browsers or governments have legislated against them.
In that situation, at the end of the day, ads will still be here, and targeted ads are necessary for ads to be useful for both user and advertiser.
These measures, where your user agent says what ads would be useful to you, seem perfect to me. For the average user, they give just enough info to ad providers to not be invasive, and for someone who absolutely does not want that, they could likely turn an option on to give random topics.
Right now though, one can argue that this actually gives more data than before (i.e. tracking + topics instead of just tracking), but try to think about the situation in the future.
(I'll still block ads.)