As much as he earned was given to his wife. as...as比较结构修饰代词much, much为主语。

= All (that) he earned was given to his wife.

We cannot, as much as I think it is right and just that we should, have our cakes and eat them too.

= (As) Much as I think it is right and just that we should, we cannot have our cakes and eat them too. 即much as引导的让步状语从句。