I do, and most of the people I know / work with / hang out with do.

But I also tried espresso without any sugar in it for a while and well, I like it more with added sugar!

Most people in Milan (Northern Italy) nowadays put brown sugar in their espresso, a minority use white sugar and a small percentage get their coffee with no sugar.

There’s also a few who put honey in their coffee, I especially like it.

These opinions are based on personal experience.