Of course, you can still model this with game theory, but you need to break "turns" into smaller units (Planck seconds, if you want to go all the way), as for iteration vs something being a one shot game, you could say either of these is universally the case based on definitions of what is a repetition of the same game, and what is different enough to qualify as a new scenario.

So game theory is not broken for real world problems, but like any theory I have seen when you scale it up from a simple puzzle to interactions with the universe you make the problem more difficult.