If voting were held on Election Day, as it used to, people who care would find the time to rearrange their busy lives to spend a few minutes, maybe half an hour, at the voting booth. It's virtually nothing to ask.
At least for me, some years, that would not work. In residency for example, my day started at 6:00 am or 7:00 am and would not end until the following morning at 6:00. I could not leave the hospital. I wouldn’t be able to vote so early voting has been a godsend for me. Even in private practice, there are many days where I start operating at 7:00 and don’t finish until 7:00 or 8:00. Thankfully those are few and far between but it still happens and would affect my ability to vote.