I think I understand you -- just a single number can never capture the richness and complexity of a life. But it's not about just using numbers, it's about doing all the useful stuff, including putting numbers (which is indeed often very important). We can't
feel the pain of a billion people -- we can only look at statistics in disbelief that so many beings are suffering so much, and try to make their lives better if we can (and indeed we can :) ).
> Which didn't stop people from trying and creating unimaginable suffering.
Aren't we already creating immense amounts of suffering by the conditions of animals (which often have terrible living conditions), preventable diseases and poverty? Why putting a number on it is more evil than doing nothing?