'Man' refers to human individuals, especially adult male humans. So the word is pretty flexible, and can technically refer to any human regardless of age.
I don't see what's wrong with calling men 'men'. I don't mind it at all, seeing as it's a descriptor of what I am using the English language. What's your problem with the word?
Sure. That's why I'm looking forward to Starship, and, in the distant future, a space elevator. But we need rapidly reusable rockets before we can build an elevator.
Plus, reusable rockets are a lot cleaner than letting them sink to the seafloor, with propellant residue inside. Or letting them burn up in the atmosphere, where heavy metals degrade the ozone layer and have other negative effects.
Ergonomics =! Energy efficiency