"I dunno, just spitballing here but...a VCR? Heh...or a TV (remotes have lots of buttons!), or a computer perhaps." Better to consider UI in relation to the po

"I dunno, just spitballing here but...a VCR? Heh...or a TV (remotes have lots of buttons!), or a computer perhaps." Better to consider UI in relation to the possible failure modes. VCRs can be complex, but failure generally doesn't risk death. Cars are probably the most complex widely used device use of which carries significant risk. Critical personal medical devices, like insulin pumps, have pretty simple interfaces. Or don't have any interface, as seen in pacemakers.