So the issue is if you let people opt out by paying you’re left with a low intent, likely lower net worth group of people to advertise to. As a result those eyeballs are worth less. The advertisers will turn to other platforms if you only let the worst people see their ads.

Unless enough people all pay, the whole thing stops working. But there aren’t enough people who will pay because most people don’t care.

Tldr: the ad supported business model fundamentally doesn’t work if you let all your best products (you) opt out by paying. It requires them to pay an amount far in excess of what they would be willing to pay for the system to work.