I remember when I was 15 or 16 being invited to a barbecue at the home of a guy who was about 17. After we had been in the garden for quite a while, it started to rain and we needed to go in the house.
The boy whose home it was asked us to take our shoes off when we went in. His parents did not have a shoes-off rule and I had visited quite a few times and kept my shoes on. Presumably he was under instructions from his parents that his guests were to take their shoes off if they went inside.
There was a girl there who had come with a friend that she was staying with overnight. She protested at being asked to remove her shoes because she was not wearing socks. Back in the mid-nineties, it was fairly fashionable to wear sneakers without socks. The boy insisted that she needed to take her shoes off. However, she refused. Her friend went into the house barefoot and made some quick goodbyes and then they left and returned to her house.
What would have happened if the house of the girl's friend was further away and they were reliant on being picked up at a certain time? Would she have stayed outside or would she have taken her shoes off? I suppose the host could have offered her some socks.
At the time, I took the moral of the story to be that if you wear sneakers without socks, you must be prepared to be barefoot. You never knew when you might have to take your shoes off.
These days people don't seem to wear sneakers without socks so much; they wear those ridiculous socks that leave the ankles bare but which are still visible. Teenage girls at a party would probably be wearing those flat ballet pumps without socks, unless it was winter and they wearing those Ugg boots. Fashions have changed an awful lot.
Of course, if you are wearing sneakers without socks, your feet are more likely to smell. If you get asked to remove them in somebody's home, the best thing to do is to ask if you can be excused and wash your feet in the bathroom.