The method of “enforcment” for that part of the GDPR is awful but for a big and fairly hated player like Reddit it will probably actually work, some organization or competitor just has to file a formal complaint. There was some NGO a few years ago that filed cimplaints against various big players and got platforms like Twitch to fix their banners that way but idk what happened to them!
Oh yeah not saying it won’t make waves for something like Reddit, it just wish it was more actively enforced from reports