It doesn't have to.
A general done with propofol and no volatile, opioid, or benzo is ready for phase 2 just a few minutes after extubation.
I do 99% of my ERCPs with prop, succ[1], spontaneous ventilation, propofol infusion. They roll into a sloppy prone position, do the case, and I turn off the propofol when they're wrapping up. By the time they're supine on the gurney again, they're about ready to extubate. By the time all the EMR clicking is done, they're ready to go back to their endo holding room (phase 2). I am never ever the time limiting factor over there.
Where a GETA slows things down is if people do their usual polypharmacy thing with midazolam, propofol, fentanyl ...
A plain old colonoscopy or EGD done with single agent propofol is a general anesthetic without a secured airway. One can do essentially the same, albeit with a somewhat larger induction dose plus an endotracheal tube, for an ERCP. And the wakeup is the same.
[1] sometimes roc + sugammadex because I hate succ, and like stiggin' it to the hospital by spending more of their money