People aren’t going to leave reddit all at once right away, because structure means that individual subreddits are very much isolated from one another in terms of users.
However, it’s likely that we will be seeing some kind of cultural shift happening there as quality get worse. I feel it’s inevitable that there will be more low effort content pumped out as quickly as possible than ever before now there is an actual monetary incentive instead of imaginary Internet points, and all personalized feed and ad is going to do is isolate individual users in their individual bubble and not allowing human connections to form between them.
Things are getting better here. The regulars recongnize each other’s name and personalitu, whereas on reddit all the usernames all blends together into an amorphous mass unless it’s one of those novelty accounts or e-celeb or something. That’s the key difference between Lemmy and reddit right now.