I can't even begin to talk about how annoying Facebook can be. Few years ago, I believed that I could save pictures on my Facebook and if I lost my phone, I could always retrieve, so I saved a lot there. Lo and behold, one random I decided to download one of the pictures because I had deleted it, it was screaming nonsense. I just out of anger, deleted them
I don't just know if they're trying to control the space (MB) of the picture by dropping quality. If I want to make a post on Facebook, I don't try using the lite version because that's where the quality drops, we use the normal Facebook which helps keep the quality.