Eating meat will be the big one. You look at history and meat was a rare treat, now it’s the main part of almost every meal.
People will watch media where the characters grab a hotdog on the street corner and it will seem both barbaric and decadent.
There’s probably something we are doing with children too that will seem odd. It takes a village to raise them after all and we isolate them with two parents that also have to work full time jobs. Can’t be good for either.