Fine, but I do flowers, which generally do not fit into the 35mm frame
Regarding the size of the equipment used, I'll just say that my rb and my cambo are very stable and allow me to use just about any lens for closeups well beyond 1:1, in fact, with the ability to tune magnification on the fly (no shuffling of extension tubes). And they use leaf shutters. Then there are the tilts that allow me to optimize DOF at wider apertures... All of which I consider to be very big bonuses.
Sure, when I am doing handheld macro shots of bugs, I'll use a 35mm. Incidentally, I am doing a fair amount of nonsense with a Mamiya 80/4 macro (for 645 format) mounted on a Nikon body. That lens is fabulous for macro, if you get sick of shuffling extension tubes (I do). Way more flexibility than a standard 35mm macro rig, and if there is any loss of sharpness, I am not seeing it (it's all a wash once you stop down anyway, how many 35mm macro shooters work at f/8? For a straight-down shot of a penny maybe...).
Bottom line, as usual, is that there are different tools for different tasks. My point was that there is no overriding reason why smaller formats are better for macro.
In the spirit of putting one's money where one's mouth is, I suppose I should end with an LF macro example. Shot on 5x7", with pushed hp5+. I do not think 35mm could have delivered the tonality I was after. Am I wrong? Really? If so then show me.