Everyone's contribution is insignificant, and yet it all adds up.

This is rather like saying the average player in a football match scores 0 goals, therefore 0 goals were scored.

No, it’s like saying how many goals you personally score is insignificant for how many goals are scored in total in football matches worldwide.

It’s like Down’s paradox (https://en.wikipedia.org/wiki/Paradox_of_voting). Being a paradox doesn’t make it untrue.