My guess is this, which is way at the bottom of the support FAQ page (which can be found at the bottom of the posted FAQ section):
“I cannot join a Steam Family”
If you cannot join a Steam Family, it is likely for one of three reasons:
- Your account activity does not show that you are part of the same household as the existing members.
I’ll happily settle for any amount more physical buttons. It sucks to listen to music using my phone because I can’t skip, replay or pause songs without using the touch screen.