Well beyond the sheer laziness of not having to drive, take the bus, bicycle, or walk to the voting place....when you're dealing with various props, measures, and candidates, it is also easier to research them while in the comfort of your own home.
Covid could be another reason people might not want to not want to go in person. It ain't much compared to where it was but hundreds of people are still dying from it.
Nah... I still don't think mailing in votes vs voting in person makes a difference. You fill out your ballot at home or not.... The person/people/machines verifying the votes and tabulating them in the total has all the power. They say if it's fake or not and they determine what vote is for what candidate and how many.
Car, gun, fist, knife, whatever method of probable future attack.... It'll be yet another reason to vote from home. And Republicans will probably say it was planned for that purpose.