This is certainly a growing trend which was first started amongst end-users themselves, and slowly we've seen a few news media outlets also following suite. So far, only a very few government agencies have actually followed. Coming to mind are also The Netherlands. What is attractive for many organisations and agencies on Mastodon, is that...
I’m not strictly against personalized recommendations (hence why I said it “can” become manipulative), and you’re making some good points. But I do think it’s a very dangerous game to be playing.
It almost certainly requires collecting and storing very personal usage data, and it can influence people’s mood and behaviour depending on what the algorithm is optimizing for (e.g. showing you stuff that makes you angry or ashamed). For that reason I think it’s not just a matter of letting it loose on people. It needs to be very well communicated and explained (e.g. things like “we are showing you this because …”), so people stay in control of their own actions.
Imo it’s a bit like slot machines. Just fine for most people most of the time, but it can drag you down a dark path if you’re vulnerable for whatever reason.