https://www.reddit.com/settings/data-request
They must oblige within a certain time frame — even if your account has been suspended and I believe even if you’ve deleted your account. Curiously, this might be one effective way to protest. Golly I wonder what would happen if many people requested such reports simultaneously. It seems these must be processed manually by admins.
As a bonus, it’s nice because all your comments and messages are searchable.
My guess would be to sway your opinion - requesting your data often happens when you leave the service and very often it’s because something on that service pissed you off.
If they take 2 weeks instead of 5 minutes, chances are you are going to calm down, change your mind and stay.