Part of the original idea was that it wouldn't even have a power button: as he noted, appliances such as toasters or landline telephones don't need power switches - it's hard to imagine how radical the device was back then. Raskin wanted to eliminate many of the ideas, inherited from 1970s-era, text-based computers, which dominated computing then and in many ways still do.
if it had thrived and grown, owners could have purchased new functionality which would add new abilities to its single, all-encompassing onboard software
the Canon Cat and the Mac that Steve Jobs killed.
https://www.reproof.app/blog/on-designing-a-more-humane-computer
The Cat was designed by the late great Jef Raskin, and there's a theory that he named it because cats famously chase mice… and he didn't like the mouse-centric computer that Steve Jobs turned the Macintosh into - Its software was implemented in the legendarily efficient Forth language
http://ratfactor.com/forth/the_programming_language_that_writes_itself.html
(as also used in the far less radical Jupiter Ace home computer),
https://www.theregister.com/2012/09/21/jupiter_cantab_jupiter_ace_is_30_years_old
and was designed to be extensible