I’ll start with some personal thoughts ranked from mild to extreme changes:

1. remove re-post button (hopefully gets rid of “virality” and “influencers”)

2. cap comments / hour to 10 (gets rid of arguments, flame wars)

3. remove like button entirely

4. posts can only been seen by friends, and no more

5. Groups only allow anonymous posts?

6. An ML model that absolutely filters out everything remotely political, hateful, etc

7. Friends are auto un-friended after 5 years