I know many, many people who cannot go that long without eating, I among them. I get shaky and have a blinding headache if I do not eat in the morning, and whenever this is brought up in conversation, I’m always surprised by how many people also have a similar reaction.
IIRC, the three-hour rule only applied to masses later in the day. They used to be very infrequent, except for nuptial masses. I never even heard of vigil masses fulfilling the Sunday obligation until I was on my honeymoon and our table mates, who were from another state asked why we didn’t just attend the vigil mass on Saturday rather than chance missing our return flight home by attending the first Mass on Sunday.
When the midnight fast rule was in effect, if you attended an eleven or twelve o’clock mass, chances were pretty good that you would not have eaten for at least thirteen or fourteen hours so it was not unusual to see few people receiving at those masses.