Vastly different.
One pedal driving implies that it’s all done for you. The car is slowing at some rate, coming to a stop. Unknown when it starts alerting people behind that the car is slowing down. And the regen is so aggressive that in some cases pressing the brake is not feasible because it will slow the car too aggressively. You lose a degree of control.
Two pedal driving implies that the brakes, including regen and the hydraulic system are used, and the brake lights are switched on. An established practice. Trillions of miles of use. No real need for faith here.
It’s not that I can’t drive one pedal, it’s that the loss of control to temper the rate of slowdown, coupled with unknown basis of when the brake lights come on, since I’m not controlling them, is disconcerting.