I will copypaste, because this feature has been discussed a lot already.

The companies will get some general data if their ads work, without a profile about you being created. I am fine with that. Just imagine what a boon it would be for the “normal“ less tech savvy, if advertisers switched to a more privacy respecting technology like this. If more privacy focused people don't like it, they can simply disable it by ticking one box, without negative consequences (unlike content blockers and similar techniques where a website can penalize you, turned off PPA is not detectable). It has no downsides as far as I am concerned. It doesn’t give advertisers additional data that they wouldn’t already be able to get, it just creates the option of measuring their ads in a privacy respecting way.

Discussion about PPA from some time ago