The majority of terminally addicted people I have interacted with at length have both recognized the terminal nature of their addiction and been unable to do anything about it.

That's the nature of addiction.

Honestly the damage done by TikTok et al is so severe that I’m okay with a little collateral damage. We will build new things.

But I also see no reason you can’t separate out forums with upvoting from the personalized engagement optimized feed. They are fundamentally different designs. (In other words, Subreddits are safe, the Reddit homepage is regulated unless it changes.)