I work at a big tech thing. But these also do a lot of good.

Facebook keeps me more connected to old friends and family than ever before. It facilities communication and organization of events that would far more time consuming to do without Facebook. I hang out with loved ones more, because pinging them is on Facebook is easy.

Sure, Facebook could be better. IMO ads in messenger is a cheap move, that won't play out well. But Facebook could also be a lot worse than it is.

You're not going to rebuild the world from scratch. Nothing will ever be perfect -- but don't let that get in the way of better. Why not make it better from the inside? How is that not ethical?