I don't really understand the mindset to "live and let live". Do parents do that? Does government do that? Do you necessarily have to be in a governmental or parental position to try to influence other's lives when you know it's for the better? People are straight up ignorant and clueless when it comes right down to it. I'd love for someone to give me great advice all the time! Even if he DIDN'T initiate these conversations, it doesn't hurt to try to help him.
Now, continuously arguing with him over it would be another story. Pointing him in the right direction sounds harmless though.
It's difficult to know from which angle to attack the situation without knowing how much he actually saves, or if he's in debt at all, neither of which have been answered, though some in this thread have assumed he saves $30k a year (no proof).
For some of your reasons so far...
- Frugality means spending to your priorities, which requires that you know/develop your priorities, which leads to greater happiness, better relationships, and self-improvement.
Frugality is more about efficiency than balancing priorities. One's priority could be travel. You could spend $2k or $200k on travel in a year. That definition doesn't explain frugality. He doesn't want to be "frugal", so you'll never appeal to him in this way.
- Post FIRE, you can do what you want, when you want
Yes, but he can do what he wants when he wants it right now more or less. He wants to keep his income so he
wants to work. His end game at the moment is not retiring.
- Thinking about money AHEAD of the wave prevents worrying about money AFTER the wave
I would start here...
We all know it's not about income, it's about savings rate. It's easier to save with a higher income of course.
I think the best way to get through is to inform him that he isn't going to want to work forever. At some point, he's going to want a change in his life or possibly quit. He's already in a stressful situation, so this could happen sooner than later. Building FU money is what he needs, not a speech on FIRE.