I was enriching them by agreeing to view ads – not granting unlimited and perpetual use of my intellectual labor. One is a fair exchange of value, the other is highly exploitative.

Reddit sells ads first-party. They have their own Advertising Account Team, Advertising Platform and more.

The only reason Reddit is interesting to advertisers is the community. You can select specific subs to advertise to, interest groups, demographics, etc. You can get "laser" focused on who you advertise to, and offer compelling adverts to people highly likely to engage with your products/brands and convert into sales.

The only reason this works is because people like you have built those communities on Reddit by contributing your thoughts, opinions, experiences, expertise, time and more for free.

I'm fine with that. That's a fair exchange of value.

I'm not fine with them using that intellectual labor for any purpose whatsoever, indefinitely, forever. The only way to win at this point will be not to play; the downstream consequences will be the death of the open internet.