Last year, while opposing Reddit’s API changes, a large number of subreddits turned from public to private or turned NSFW (Not Safe for Work) to impact ads on the platform. To prevent this kind of change, Reddit is bringing new rules where moderators will have to submit a request when updating community-type public or private or maturity ratings of SFW (Safe for Work) or NSFW.
The answer is simple: Even a single popular subreddit has more users and content than all Lemmy instances combined.
That ‘mass migration’ a year ago made Lemmy viable as a social network, but barely affected Reddit at all in terms of numbers, and numbers are all they care about.
I’m still here on Lemmy, but to the Vast majority of Reddit users, nothing has changed (at least not enough to leave the place where all their communities are)