The updated design of that state machine looks so bad I stopped reading there. Either the author isn't the best person to be making these arguments or are being

The updated design of that state machine looks so bad I stopped reading there. Either the author isn't the best person to be making these arguments or are being disingenuous to support one. I do agree with the overall take, "it depends" which is where you end up when you get enough experience and can also be able to articulate when/where and why. As others mention, I find that being able to represent invalid states (and function calls for that matter) in static types is well worth it up to a point. The other thing I want to say is that you can have a state machine without a thing called a state machine, it's basically what the app is doing regardless so there's really no way of getting away from it, it's a matter of whether you build it with that clarity or not. For the record I prefer implementations that are state machines rather than ones that use an abstraction called a state machine (as the former is a 'zero cognitive-load' abstraction).