My profile is also ridiculously inaccurate. Though I do use ublock origin, privacy badger, etc and disabled most tracking features in my google account. Also on VPN pretty much all the time. I‘d really like to see the ad profile of someone who is completely transparent and doesn‘t spend any effort to obfuscate at all. I‘d imagine it would be much more accurate.
Interestingly my instagram ads are incredibly on point a lot of the time. You cant really hide your behavior in the app so the get a really good picture, probably.
I guess it doesn't make a difference to them, as long as they get the ad revenue from Pampers