You can't have your cake and eat it too.

Fundamentally the problem with living forever goes beyond billionaires. People get stuck in their ways of thinking, the mindset of living forever is completely different. Why should I even listen to someone who only lives a mere 40 years? What is a suitable punishment for someone that lives forever? How does it change murder?

Philosophically, living forever may be corrupt by nature.

The only way to tear down tiers of society is for some of those tiers to literally die off.