If you think about it though, Facebook is many apps in one. It's a marketplace app, a social media app, a videos app, a specialty camera app... the list goes on. Sure, you can call them 'features', but for other businesses these would be entire products. Everyone complained when messenger was rolled out into its own app (now Facebook wants me to download two apps??), so maybe the size is justified. I don't personally use every feature, but I'm glad that I don't have to switch apps to use marketplace and live videos, both of which I use quite frequently.