Not much at all, in general they are harder to ride. Especially in hilly places.
There are less gears so that aspect is maybe easier to fix. Slightly lighter due to less gears, but it is only slightly. Maybe other things?
It’s a bit like iPhones of old, crossfit, and veganism. You won’t ask about them but the people who use them will tell you about it anyways.
That bike football sport is very entertaining. They must use fixies. I could watch that all day.