I first voted by mail here in Minnesota during the early part of the pandemic, when they temporarily suspended the requirement to have someone (either another registered voter or a notary) witness you mark your vote and complete your ballot.
After that I did it again a couple of times, but since I live alone I had to rope in a co-worker once, and make a point of meeting up with my very-busy sibling another time, to act as witnesses. I could bug one of my neighbors, but for me it’s easier to just walk the few blocks to my neighborhood polling place on election day, and I don’t have to bother with requesting a mail-in ballot, or worry about sending it back through the mail or getting to a central location where I could drop it off, or be concerned with any deadlines beyond remembering what day is election day.
In general, though, I support mail-in voting and would like to do it if it was a little more streamlined.
I’m curious, do all states require a witness for mail-in ballots? I assume so, but I don’t know.