It seems to me that FB is still a little short on ecological engagements. At least, compared to Google.
So, room for improvement.
About privacy concerns, for example: FB is not guaranteeing anything about not mining your private messages. What I find when googling it does not reassure me neither.
https://en.m.wikipedia.org/wiki/Facebook
Read the controversial section. Even that is missing a lot and the citations are removed.
Facebook has been used for genocide, mass cultural appropriation, raising anti-ism sentiment, etc by military, government and terrorists.
They don't employ enough moderators likely intentionally in many regions. African continent has less than a 100.