For example if one person knows two correct facts about a specific sport, and another person knows those same 2 correct facts as well as 2 false facts, and doesn't know which 2 are true or false, isn't the second person less knowledgeable about that sport than the first person, despite technically having the same amount of true facts on the subject?

Equally, even if the amount of known knowledge in the world remains the same, isn't a world in which every human while studying spends every minute learning true stuff vs. spending half their time reading made up stuff, won't people on average be less knowledgeable despite the fact that no global knowledge got destroyed in the process? (Ofc there's never been a time when it's possible to spend 100% of the time learning completely accurate stuff, hypothetical exaggeration there.)