The original Mac was very easy to use. It became much less cognitively accessible after MultiFinder was introduced. Apple then added “SimpleFinder”, but that never truly made the transition to OS X (the name was preserved without the CamelCase, bit it is much less useful).
iOS is following a similar path, but without SimpleFinder. This impacts not only the legally disabled but also everyone who is less gifted – and the elderly.
iOS needs cognitive accessibility controls and considerations.