Have anything more than a nice sounding quotations? Like actual evidences?
A world where the richest live forever would be a dystopia frozen in time.
It would defeat the point of inventing anti-aging biotechnology by people not having access to said medical technology.
Also, last week's UK Remain vote is a pretty good indicator how old and young people think different. Young people today consider themselves more global, while old people are afraid to loose their national identity and pride. Both are OK, but as long as the young keep replacing the old the current path of humanity will, in a few generations perhaps, hopefully lead to global unification. On the other hand, if everyone suddenly became immortal it would put the world in stasis as the ones who currently hold the wealth (overwhelmingly the boomer generation) would cling to what they own and their ways of thinking instead of passing on the torch so to speak.
If humanity discovers immortality before we become an expanding multi-planet and post-scarcity society it will be an absolute disaster. Because immortality doesn't change human nature.
Imagine a boot stamping on a human face - forever.
There's also no guarantee that we have further moral progress in the future, especially when you consider the last century's two global wars.
People always love to think they're at the pinnacle. The future will be far more fantastic than either of us could possibly imagine, because it will be imagined by people who grow up learning from the mistakes we make today.
Imagine if King Henry VIII had somehow figured out immortality. Do you think humanity would be better of today, some 500 years later, with him still sticking around and laying claim to the place? Pretty unlikely, right?
Equally, what right do you or anyone else living in this time have to steal the future from the generations that are to come? They will look back at this time and wonder about our ignorance, intolerance, and small-scale thinking. And fortunately both you and I will be long dead so as to not embarrass ourselves too much with our primitive ways of thinking.
Max Planck said "A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it."
A world where the richest live forever would be a dystopia frozen in time.