You must realize the world and humanity is bigger than you. Some people with low blood sugar would be very weak without breakfast (ie my wife and most of her family, tested repeatedly under various real world situations ie in wilderness). Some thrive like that. Some, like me, don't care if they have or don't have breakfast, nothing visibly changes for me (unless I want to bulk a bit from ie weightlifting or generally doing very strenuous activity especially if its multiday).

Another case point for each' uniqueness - you mention you just drink black coffee on empty stomach. On university one of my classmates went through mandatory military service back then and he did exactly this. He utterly and forever destroyed his stomach lining (as per doctor's findings it was due to that coffee habit, even sugar or milk would help but he didn't know) and till end of his days. Tons of basic food that would make him cramp painfully or shit badly for hours. That he achieved within 1 year while you did 20 years of same seemingly without any issue.