How about wearing sneakers instead of socks in summer?

I personally don't think so. Sweat a lot in summer, and the sweat on the soles of your feet will attach to your shoes. Over time, shoes will have a taste, and feet will get some foot diseases when they are wet for a long time, which will be even more uncomfortable. It is recommended to put on socks, the kind that absorbs sweat, and you can take them off to bask in the sun when you don't wear them. It's good for feet and shoes.