The only thing life extension will get us is a very powerful class of ancient people that will have ownership of just about everything. The only thing that resets the clock on wealth accumulation under the capitalist system is death. No matter how much of a grifter you are the grim reaper will force you to divide it amongst your heirs. But if that no longer happens and if capital keeps begetting more capital then the end game would be a very sober one for an even larger slice of humanity than it already is.
Interesting story on this theme: