Is there a human being who beats a computer in a game of chess?
Yes, but not to the best chess-playing computers, which learn by playing against themselves and their mistakes against opponents, as far as I know there are human-machine team tournaments
Last century yes, but today it is impossible.
While current world champion Magnus Carlsen has the highest ELO ever achieved by a human 2881 points. Computers have taken chess to another level, AlphaZero has reached 3400 ELO points.