Very sensible if you are driving a manual gearbox, especially if you are on a slope and need to balance clutch and accelerator and handbrake; but auto gearbox technology has moved on.
My car does not have a handbrake, only a foot operated parking brake. It is not intended that this foot operated parking brake should be applied when the car is brought to rest for short periods.
If the parking brake is applied and the gearbox put into "park" or "neutral", then it is necessary to apply the footbrake again before engaging drive and taking off the parking brake. Much more sensible to simply apply the footbrake. The auto gearbox fluid flywheel is designed to allow the car to remain stationary with drive engaged and no damage will be caused. There is no equivalent of riding the clutch, nor the danger that results if a foot slips from the clutch in a manual car at rest with a gear engaged.
A major reason for choosing an auto gearbox is specifically to avoid all the hassle of applying handbrake, going into neutral, re-engaging gear and balancing accelerator, clutch and handbrake that is an essential part of driving a manual car.
Of course, if the traffic is brought to a halt for an extended period, it makes sense to apply the parking brake and select neutral and relax. But for normal stop-start driving in traffic, absolutely not. And before someone suggest that leaving my car in gear for short stops wastes fuel, let me point out that the overall consumption of the IS 250 auto is actually better than that for the manual version . . . . . . .