I feel the author really meant that it's ok not to be obscenely rich.
Of course having a sizeable amount of savings is important for all the things you described. Yet the "low six-figures" income of her first example is probably largely sufficient to handle these.
I wish she had said that explicitly at the beginning, a low six-figures income is rich enough for me but making that money is almost as hard as becoming obscenely rich. After you reach 80-100k a year working for someone else it's a very large and all consuming step to make it to the next rung of the ladder.
In California, a family making low six-figures is upper-middle-class (my parents made ~$80k and we were generally considered lower-middle-class). So it makes sense to me not to call that "rich," though of course the value of money is a personal thing.
You're right that location changes the income levels quite a bit. I would need much more in California or New York to live as though I felt rich enough.
Of course having a sizeable amount of savings is important for all the things you described. Yet the "low six-figures" income of her first example is probably largely sufficient to handle these.