On the flip side, going out to dinner with friends, and discovering that you may be on the hook for $100, and not stressing about how you are going to pay for it, is withing reach of a lot more people. I have several friends who have reached that level.
I think the levels are pretty good. Though I would also add two levels of wealth that materially change people's happiness - L0 (Can I pay my bus fare, rent, groceries without stressing. L0 is very, very real). And also, L4 - which is no longer flying commercial. Being able to go where you want on your schedule, without ever having to walk through an Airport/TSA is, I have heard, a material change to personal happiness.