Focus stacking also lets you avoid softness due to diffraction. Shooting at f/8 at 1:1 magnification is equivalent to f/16* at infinity, so you definitely have some diffraction softness already. If you go beyond 1:1 it starts getting pretty crazy. I shoot coins at f/5.6, which for small coins like dimes is
barely enough to get the whole relief in focus (or even not quite enough); that's already into diffraction limited territory, with a very flat subject.
I was really delighted to realize that the R5's high frame rate would let me do hand-held focus stacking. This was
literally my first attempt at it after getting the camera. This wasn't even a completely still subject (the spider only had one line but the focus stacking rendered it as several because it was fluttering in the breeze). It's pretty small; this is close to 1:1 magnification with a bit of a crop.
* This assumes some specific details about the lens's optics, but it's usually correct, or at least close.