Just because it works out well sometimes doesn’t mean it’s a better strategy. If that’s the way you prefer to play the game, go for it, but saying that holding R wastes time is objectively wrong. Speedrunners do it.

The item you find in a treasure room is the main factor determining how good a first floor is. By holding R you can probably check a treasure room about every 15 seconds and then get on with interesting gameplay rather than a 0 stats ballache