Sometimes the photo is good in theory, but not quite as sharp as I would have hoped for. This happens because I way overuse wide apertures, such as in this photo - an aperture of f/1.2 with a 50mm lens on a full frame camera.
It is very difficult to focus properly.
This is one reason why I might swap my current camera to one that has better autofocus... I mean, mine's excellent, too, but the new Canon EOS R3 has even better one.