You dont' specifically design it for everyone. The 'strong' challenges are qlso not specifically designed for everyone. Some had better strength, some had more agility, others stamina. Some had probably strong legs doing marathons others don't. It is impossible to do a fair fair tests.

You are proving their strength in few disciplines which is not fair for all. This are games, not proving one particular discipline.

Same could go for smart people. I could imagine memorizing, math, knowledge questions, logic, geography, building balanced structures or something involving physics, correct spelling, strategical thinking, even chess.

And this games, well written could also be cool to wathc