You can't judge your own abilities without comparing yourself to someone else

Leon Festinger proposed that people have a built-in drive to evaluate their own opinions and abilities, and when no objective yardstick exists, they measure themselves against other people instead — usually those close in ability, not the best or worst. Which comparisons feel natural shifts by context: a runner checks their time against nearby competitors, not the world record holder. The theory became a foundation for later work on envy, self-esteem and status anxiety.

— Leon Festinger, A Theory of Social Comparison Processes — Human Relations, 1954