I've noticed that holding the door for others is so ingrained in most of us that this is one habit that has persevered despite the virus. Enter the store and start down an aisle and if someone enters the aisle from the other end the approaching customer may well stop and retreat. A lot of folk try always to keep a safe distance from others, strangers especially.
Line up at the check out and everyone is standing on a big, brightly coloured sticker. Each sticker is six plus feet away from the next closest sticker. I say six plus because in Canada many of the stickers are a full two metres apart and two metres translates into almost six feet seven inches in Imperial measure.
Holding a door breaks the distance rule. Oh well, I think it's worth it. Hey, the doors are often outside, it is only a moments long violation and we are wearing masks. 😊