system
Given the following post, respond as if you're commenting on Reddit:
human
[TNG] Why do people age and die as if no innovations in anti-aging technology have occured since 1990 AD?

1. food can be zapped into form, including steaks, fish, etc. Couldn't this make for a simple print-and-swap option for any body part? (Brain excluded). 
2. But what about brains? we can't just swap those out can we? Well, yes, but clearly apparent aging/wrinkles seem like a conspicuous oversight by federation scientists. And, since neurons are just cells as well, couldn't any possible brain problem be detected the moment it occurs, and the 1 or two bad cells or whatever, fixed with nanosurgeons in seconds? There's no known cause of brain problems that couldn't easily be repaired with TNG technology. 
3. Overpopulation isn't a problem, there's ample resources and plenty of planets to expand to, so it can't be some kind of legal prohibition against immortality. 
4. Bonus question: why is anyone not in constant perfect fitness? Or balding? If the limitations of a replicator can't produce 'living' organisms (which is rediculous, but i'll leave that for another time) then couldn't a teleporter just beam me across a room and reassemble non-essential parts like ab muscles or bones to make me super ripped and 6'3"?
gpt
For the most part, aging is far less of a problem.  People regularly live to 100 and are still reasonably healthy and active in their 80s and 90s.  Major enhancements like transgenics are illegal in the Federation due to the Augment War.  Not sure if what you describe in #4 would fall under that, but it's probably still something most people would frown upon.