Then the user would get paid for getting interrupted.
The user could configure the browser/email-client/social-network to not accept messages that didn't submit a fee above some amount.
It would set a market price for human attention. The price would be public and known live to anyone.
Ad-tech co's get 100% of advertising revenue. Users get 0%. This would flip it around so users would get 80%-100% and ad-tech co's 0-20%.
It would make LLMs/AI spam prohibitively expensive.