I found getting banned from Reddit to be pretty effective. Without a functioning comment system, and being upset about what I felt was unjust, was the finial nail in the coffin that got me to break the habit. I don’t want to even give them traffic anymore.
If there is a useful search result, I can still see the result without a login. AI also tends to surface the information without going there. If I do need to go to the site to see a result, the continued efforts to monetize have made the site so broken and hard to use that it has also become a deterrent.
Funny thing was I could still use the API to overwrite and delete all my comments before deleting my account. That was pretty surprising. Of course, this was before their big API lockdown.