That list is out of date - there's an updated version on wikipedia: https://en.wikipedia.org/wiki/Visa_(document)#Visa_restricti...

Not sure if "powerful" is the right word either. It's more of a list of the best passports to have if you want to go on holidays. "Doesn't require a visa" usually means those countries don't require visas for short non-business trips (anything from 14 days to 6 months). E.g. you can visit the US with a German passport for 3 months for a holiday but it's extremely difficult to get a visa to move there indefinitely.