More likely that he would live most of those years with compounding mental and physical health issues, quality of life degrading to the point where most would wish for death instead.

This is a common misconception. Namely, that increasing lifespan just means extending the part where your health degrades continuously. That's actually a very unrealistic outcome for life extension technology. In general, the things that cause your health to degrade as you age are interlinked with the things that cause you to die. If you find a way to increase lifespan, chances are you've also found a way to increase healthspan. In fact, all of the best methods we currently have to live longer do exactly that (e.g. exercise, eat healthily, avoid smoking, etc.).

What an un-hacker ethos: the idea is to continuously fix problems so that, if anything, quality of life improves from year to year.