Im a layman... but how do you measure social medias impacts, when everyones algorithm is different? If everyone is on it but having a different experience, how

Im a layman... but how do you measure social medias impacts, when everyones algorithm is different? If everyone is on it but having a different experience, how can that be measured? I imagine some are better at being resistant to it and can subconsciencly push it to more positive direction and ignore the depression-bait it starts feeding them when IT knows they are down... I was in a severly nacassistic relationship for years, and while I'm mostly over it, those few times a year I log into facebook, all it wants to do is remind me of it and feed me all this victim crap. It can't be healthy for a young mind to be staring at this all day, its absolutely manipulating. It's kind of messed up.