On Android 6.0, Facebook must ask you for accessing your contacts, location and doing most sensitive stuff. You can deny it those things and the app will keep on function normally. To their credit, Facebook is a lot quicker to update their app to work with the more restrictive Android 6.0 permission model than others.
Combine that with something like Greenify that will stop the app from doing stuff in the background and killing your battery, and it's actually a better experience than the mobile website. It's just insane on how much you must tame the application to be acceptable to use. Wish Facebook engineers would take note of how bloated and overreaching their app is by default.