I actually saw an interesting documentary on Netflix about the history of elections and voter suppression. The US is one of the few nations that has election day on a random Tuesday in November. They gave a good example for why it is an inconvenience for a lot of working people. Imagine if you are a single parent with 3 kids that you have to get ready for school, you have to go work and can't get off in time to go to the polls, and have multiple after school activities, you could easily miss the window to vote. I could see this being an issue for a large amount of Americans.
A good amount of nations either have multiple days you can vote, make it a national holiday, or offer it on the weekend. After filling out my ballot I could totally see how you can also mess it up. If you don't read every step carefully your ballot can easily not be counted.