I don't think very much is fair about anything in that picture, but I also don't think we should hold back advances or treatments while we work that out, nor do I think that it's particularly useful to relate those two phenomena specifically, you could as well say "Is it fair we use jet-skis while those stuck in poverty making our products have such a poor quality of life? Is it fair to use iphones while those stuck in poverty making the iPhones have such a poor quality of life?", and to be honest I'm slightly inclined to say "no" to that last one...

Significant longevity treatment is likely to be highly disruptive to our society in many ways, but I don't think that we should either fall for the fallacy that we can accurately predict those ways, nor succumb to the idea that we won't or can't adapt positively.