In states with low population densities, like Utah, Vote By Mail makes sense. Even in Texas, persons over age 65 can Vote By Mail, and that works well.
For the primary in Ohio my husband and I received applications for mail in voting. We each got 2. This was done by De Wines daughter. The catch was that it was not postage paid. She lost. Had she sent postage paid applications she would have done better. Even requiring a stamp is too much for some voters.
Actually, Utah has a very high population density.