One-pedal driving trains a driving habit that could lead to a regrettable mistake when getting used to a vehicle without it. The driver's seat is no place for poorly considered conveniences.
Other cases will arise: someone driving nothing but one-pedal for 7 years, suddenly finding themselves without it.
There are going to be new drivers who learn on one-pedal and drive nothing but that for years, so all their core habits are formed around that.