Several years ago I worked with a guy who got 4 hours or less of sleep a night. He was the most alert and well-rested than anyone I worked with at that place. Trump is also famous for this. Science actually calls these people short sleepers. 1-2% of the population can get by on a short amount of sleep and be fine.
I used to get 5-6 hours at most for the longest time when I was in my 20s. I was definitely sleep deprived during that time though. These days I have to get plenty of sleep. I acquired a chronic illness a few years ago and if I don't sleep upwards of eight hours I become crazy symptomatic.
Thomas Edison slept 4 or 5 hours a night, every night. He said that was how he got so much done. He also slept on his lab bench to save on transit time back and forth to his home. He had 6 kids, one of whom lived to be 104. Edison died at 84 of complications from diabetes.
I can get by with 5 hours of sleep for one night. When I was younger, I could do 2 nights like that in a row. Typical for me is 6 - 7 hours.