Voter suppression is definitely a big problem. I am all for making voting easier for everyone, but I don’t think declaring a holiday is the best way to do it. Even if Election Day is declared a holiday, many people are still going to need to work: hospital workers, police, fire, retail, just to name a few.
Instead, I would like to see making early voting available in all states, moving Election Day to the weekend like so many other countries do, requiring businesses to give workers time off to vote, eliminating the practice of gerrymandering by political parties, and reducing the myriad of other voter suppression tactics. These will probably do more to create participation than merely creating a holiday.