I think you need to revisit this in 10 or 20 years. I think you'll have a different opinion on this number.
$10k is not comfortable. That is poverty. And the question wasn't what is possible to survive on.
Again, I apologise if my comment/s seem impolite. I am not having a great day, but I don't mean to come across as disrespectful. I understand that I live in a different world to many of the people here on HN. I also think we may be talking past each other a little bit, using different definitions of "comfortable". I think it's possible that I don't know what comfortable is supposed to feel like, at least not the way most people here seem to be using the word. To me, comfortable is just having a loaf of bread in the cupboard, a roof over my head and a healthy body. I feel like that is all I need, and that's the point I was originally trying to make.
You might be happy as a PhD student, but your housing and life is entirely dependent on the university. You are one academic violation away from that all being in jeopardy.
What happens if you get a spouse and child? Will your current housing and savings be enough to support them and yourself if you both decide you want to stay with the baby instead of working?
What if your government passes legislation that costs you your job, your housing, or your healthcare?
The $10m money is about not worrying about anything other than global economic collapse and/or massive wars.
"Not worrying about money again" means never again. Not just while you manage to hold down a job.
I really like the peace of mind that gives me and everyone, even if that means I have to pay more taxes.
That's certainly better security, but it's still nowhere near the level I'm talking about. You're still having to concern yourself with money for things like smartphones, entertainment, holidays, etc. and you're one government crisis away from austerity taking a big chunk of that away. Also, keep in mind that there are still people alive who witnessed WW2. You can't take the stability of your country as a given.
The $10m number puts you in the position to even diversify away risks to your home country.
From the data it does not seem to make people here lazy, and being long-term unemployed is still bad for mental health and being part of society. I am not sure how much of this is cultural since it is surely connected to attitudes towards work.
Sure, but you're comparing apples and oranges. Almost 2 of those orders of magnitude disappear when you change $10M of assets into a few hundred thousand dollars of annual income.
A lot of the rest goes away when you notice that not worrying about finances "ever again" includes an awful lot of expensive things you don't pay for day-to-day or even year-to-year, such as the dental work you're putting off.