Obviously most people disagree, but I don't think we should search for medical advances that make life significantly longer. We should search for ideas that make the finite life on this planet significantly better. A longer life is dangerous. If people could live 150 or 200 years that will make the problems on this planet much worse since the desire to accumulate wealth over that time would be insane.
Older generations try to take in new ideas - about homosexuality, racial equality, universal human rights, whatever else you can think of - and raise their children with those ideas in place too. And most often, those children find out later that the older generation didn't really believe in what they were saying, at least not to the extent of being able to overcome their own childhood programming. But because this new generation was raised with these new ideas, they're actually able to internalize them and progress society further.
Having older people with stagnant ideas and larger and larger accumulated wealth and power, would be a disastrous headwind against social progress.