But opening wide can work in photography.
Here are two similar shots, and you can see the difference in the background. The f2.8 background is very smooth and blurry and non-distracting. There is more background detail in the f16 photo that isn't as pleasing to most although it might be to some.
The f2.8 image is also focus stacked, which means that it is a combination of several images. I focused separately on each of the little blooms and one on the big centre bloom although that one could be better. At such a big aperture (opening) depth of field is very small, so I needed to combine images. At f16, however, all I needed was one shot.
And by the way, that big centre flower is smaller than my thumb. The flower is Erigeron (or fleabane).
Since I'm at it, here's another erigeron photo of just buds.
But here's where I made a mistake with aperture. I shot both Sue and her sister with a wide, f2.8 aperture. I focused on Sue and she is in pretty good focus, but Heather is blurry on this closeup.
Farther away with full body shots, the same wide aperture was good enough.
Live and learn.