Why are you assuming they're pretend choices? Players make all sorts of choices in my games that completely change what I was expecting. That's half the fun of playing a TTRPG instead of a CRPG.My argument is that what people claim as sandbox play is just regular play with a thin veneer of pretend choice. The players can choose A or B or C, only so long as the DM approves of those choices of course, and, if the players choose something, the DM then prepares that something, develops that scenario, the players then play through that scenario and then choose the next scenario.
Typically the DM has various events and whatnot going on in the setting to provide hooks that lead the players to one or another story.
The players are simply driving down whatever roads the DM provides. At no point do they get to make new roads.
I may ask what direction they're taking so I can figure out what to plan for the next session, but I only ever have an outline of what will be there. Back to the car analogy the roads there are but they regularly ignore the roads, head straight into the ditch and continue going across the field. That's all in addition to the fact that if they have a choice of going to new York instead of Boston but then somehow end up in Philadelphia.
Just because they can't suddenly decide their car can fly it doesn't mean they can't choose the direction to go.