Is the very first example not one without hierarchy and thus just a state machine?
Technically yes, that's just a state machine. On https://statecharts.dev/what-is-a-state-machine.html the website itself also admits that that example is a "simple state machine", and on https://statecharts.dev/what-is-a-statechart.html you get the better explanation with
> A statechart is a state machine where each state in the state machine may define its own subordinate state machines, called substates
Technically yes, that's just a state machine. On https://statecharts.dev/what-is-a-state-machine.html the website itself also admits that that example is a "simple state machine", and on https://statecharts.dev/what-is-a-statechart.html you get the better explanation with
> A statechart is a state machine where each state in the state machine may define its own subordinate state machines, called substates