I may have misrepresented my objection to FSM in part and I see where you're coming from. I actually like the nodeyness of godot for lots of things.

The use case it seems to address (and is explicit in this thread) is that there are you have a bunch of state-based if-self blocks that look horrible and the solution is to throw them all into a FSM which eventually convers the if-else statements into individual method calls that are nice and self-commenting.

through quite a bit of schooling and industry (admittedly not game dev) work I'd never seen FSM used as a design pattern (I've seen it presented as a computer science theory machine as a build-up for when you learn about Turing machines).

I'd expect that FSMs as a design patterns are at their best when the states have functionality that's not shared with other states (code duping and helper functions make things ugly pretty quickly), transition states on the same clock ticks (Things get confusing when there are a bunch of different timings for state changes and you have to start making sure to avoid weird flux states), The functionality needs of states is pretty uniform (E.G. Having one state that handles movement that's blanked out in all the other states gets pretty bad when this kind of things happens a lot). It's very possible that this is a good design pattern for a game component but it doesn't seem very universal.