Why does no one who considers interstellar travel possible in the future seem to consider life extension as a possible way to get around the travel time?

I mean I've seen people propose things like frozen embryos, cryo, simulations/uploading, generation ships etc. but never the thing that'd actually enable the loved ones (no matter the economic class as even if you think only the rich would go into space, as long as they're not all fleeing Earth at once to technically all be astronauts not only rich astronauts could get it) of those making round-trip trips to distant stars to still be there when they get back