Author here. Absolutely right what you said about being easier to grok.
Shortly after this was merged to main (though under feature flag) another dev had to fix something and commented something like “I just fixed X in two minutes which would have taken me hours before”
And since you mention state machines: most of the handlers are done as state machines.
Plus the overall app state is done as a kind of reverse state machine where we derive the status from various app states. I would like to change this to not be backwards one day but it was too big of a lift to change everything at once!
Shortly after this was merged to main (though under feature flag) another dev had to fix something and commented something like “I just fixed X in two minutes which would have taken me hours before”