It’s long running, so you want a database so you can store your state. If you’re storing state, locking it into a state machine makes sense.
I do agree with some of the commenters that making it closer to an event source design would make more sense still.
I assume it’s the standard inertia-type reasons: doing nothing is easier than changing a bunch of stuff, not changing involves fewer unknowns, and they probably have ad blockers and custom rules that mean they don’t personally have to deal with the worst of it.