> I still don't understand how voting in person is supposed to be any more problematic than e.g. buying groceries in person. Wear a mask, stand six feet apart etc., what's the problem?

Grocery stores don't have checkout lines that are hours long where you are standing around near the same group of strangers for an extended time.

Worse, the states with the longest, slowest voting lines also tend to be the states with less stringent mask requirements, less diligent enforcement of the requirements they do have, and more people who ignore the requirements.