facebook literally obfuscates their UI to stop you turning off "features" they want to push on you

it is a UI designed to be hard to use

You're talking about two different things here (and I'm not condoning either, to be clear.)

1) UI = a clearly documented way to configure all features and make the software work exactly how you want.

2) UI = load a web page and try to do the thing you wanted to do (in this case communicate with some specific people).

FB is clearly terrible at 1 but pretty alright at 2.