Anything that qualitatively changes what survival means to us, will change someone. For good, bad, indifferent. For most people a combination.

A close friend gave me insight on why success changes people, after I hit a milestone that mattered to me. He told me, "You are still going to have problems, they are just going to be different problems."

Each of our moral outlooks, stability, suitability for state of life, relatability, etc., is heavily dependent on our relationship with our survival environment. And success radically changes that relationship qualitatively, when it changes it much quantitatively.