Well, Bobad, I used to work with a guy who insisted on wearing boxers with shorts. Long-johns would have been prettier, really. Really. This was in the days of stubbies.
Sandals are cooler (thermally) than shoes, and sunburn on your feet is not to be recommmended. Also, socks make shoes that you are not used to wearing much more confortable.

Some years ago, a young lady commented rather unfavourably on my dress sense. I pointed out that I would not take sartorial advice from someone who wore leg-warmers.