Elderly Billionaires May Become Immortal, Compounding Wealth Forever

Nah, they’ll only live as long as their least trustworthy staff or least reliable part lets them. Or the ship of Theseus kicks in and disqualifies the android/ai from claiming it’s the same person. Doctor who had fun with this.

Perhaps better to say that the momentum of massive piles of money continue independent of their purported driver.

I think this idea is naïve.

The progress of medicine have never been perfectly distributed, but they are mostly widely available after a relatively short time.

I don't see why any process of life extension would not follow the same pattern.

The power of wealthy/powerful individuals is directly related to how many less wealthy individuals are willing to work for them in exchange of money/power.

A rising tide is lifting all the boats.

If you take the opposite stance, would reducing humanity lifespan be a good thing to fight inequality?

I think this is the opposite, regardless of income/wealth/power distribution, at the individual level, a longer lifespan would increase freedom and real wealth.

Wealth already compounds forever due to inheritance.