I've always wished I could have an ad free internet experience, I'd happily pay whatever revenue the ads would have generated.
Would it be terrible is GPT replaced ads with subscriptions? Of course they'd have to split the income with the sites they get the info from. Much how ads on a website make the ad network and the site owner money.
My guess is, if you look at what a subscription would actually cost to cover what ads do right now, it would be a figure so large per person that most people wouldn't pay it.