Everytime I intentionally interact with Meta's apps/data factories, I feel a bit like in the movie Matrix when Neo is disconnected from the Matrix, wakes up from his pod and sees the other pods. And have to admit I saw that movie when I was to young for it and that scene really did a number on me.
I don't mind being public but I mind if I'm in a way a slave to an entity that uses that to farm my identity and distorts my perception of reality.
If they farm your identity, they do so whether you post online or not. The only way to not contribute is to practice no identity. In that case your biomass still serves as a battery somehow (the movie fails to explain the physics here.)