Why would you want 100 people to have wealth instead of just one? I feel there's some related questions about utility being non-linear that matter here
No, because you can make the same argument against any improvement in efficiency and productivity. It's like arguing against division of labor or automation in a factory because less people will be employed by the factory. It's anti-prosperity.
Eh, let the market place organize in a matter that promotes efficiency, and if you really want to re-distribute, use the tax system.