Reddit mentions of Mind Engine

The physics most SF writers have to ignore to create familiar settings is a mile long. Much SF translates western or pirate movie plots to SF settings, so paying too much attention to gravity isn't a priority for those subgenres. For hard SF which respects Newtonian physics, Hal Clement's Mission of Gravity is old-school, but it has a high-G world with plausible aliens. Robert Forward's books are more recent, and he was a physicist who got gravity right. In my own work I do the math and fit the plot to the physics when necessary. In Mind Engine a ship has to get from the Kuiper Belt to the inner solar system quickly. It would have been convenient to do it in a few days, but the deceleration would've squished the crew.

Usual term for this is transhumanism. It's used in lots of SF. Best book I've read about it is Mind Engine. It presents both the benefits you mention (immortality, health, productivity) and some dangers (elitism, oppression, rogue AI) and leaves you thinking.