55% of Americans have hourly jobs, most of which do not control their hours. There are many polling places, particularly in underserved communities, where it can take multiple hours to get to vote. Elections are nearly always held on workdays. So if you are a single parent working an hourly wage job from 8am to 6pm and the polls close at 7pm, would you vote? The voting process is difficult in America for some people and easy for others.
While I'm a big fan of vote by mail, it's not the only thing. Having early voting options would also help that hypothetical person as they can vote in person on a day they don't work.
The vast majority of states have no excuse absentee voting and/or early in-person voting options. In addition, employees are legally required to allow time off to vote, though in the overwhelming majority of states, the early voting options make this unnecessary.
If people want to participate, they have many options.
I've found that if you need to argue edge cases (single parent, hourly schedule that almost completely overlaps poll hours, no absentee, no early voting or mail-in, and an employer that violates law) as you have in your post, you do not have a compelling argument.