Copious case studies indicate retargeting proved useful for businesses and customers by providing them offers/discounts in items the latter sought. It isn’t AS intrusive, damaging and risky as you suggest, there are no pop-ups or mendacious clickbaits.
Stating that the little “x” offers no guarantee in opting out, shows you haven’t tried it or did just once. It generally learns from your behaviour of visiting websites and it can stop if you choose to walk out. Google won’t ever irk a user based on an advertiser’s choice (takes balanced care of both).
I understand people chose to opt out because it was troubling. The beginning was stumbling but it is improving and helping brands in a way like never before. And by all accounts yes, I am in the adtech business. Discovering the other side of the table by myself and discussing with users/customers as yourself, to better shape the industry.