I don't think you ever feel truly rich until you reach the stage where you have the sort of money in savings that could buy a second house somewhere with cash, on a whim if you wanted it.
The more you earn, the more you spend on better, nicer things. A better car because you tell yourself it's safer and more reliable, a better house in the catchment for a better school, or private school fees, better holidays, better quality food because it's healthier, better quality clothes and furniture because you know that it makes sense in the long run, buy cheap, buy twice. None of this feels extravagant, it feels sensible, discerning and grown up.
Your council tax becomes more expensive. You take out contents insurance to protect your investments in the home, because they cost you a lot of money. Poor people don't have that because they can't afford it, and have nothing of real monetary value anyway.
You start paying much more into a private pension, you do all sorts of things that people who are hard up would like to do but can't. But that doesn't make you feel richer, it just makes you feel more secure and more financially 'sorted.'
You could be much richer if you chose to live like a much poorer person, but no-one really wants to do that through choice, do they? Because what would be the point of striving to achieve in your career, with all the rewards that brings, just to live like someone on minimum wage topped up with some in work benefits?
And even if you cut back on everything non-essential, moved to a cheaper house in an undesirable area, ate cheaper food, bought the cheapest school shoes for your kids, didn't have holidays, home dyed your hair, and managed to amass loads of savings, you wouldn't feel richer, because you wouldn't be enjoying any of the benefits and comforts that more money brings. You'd certainly be richer, but it wouldn't feel like it.