As someone very poor, for me good life means having money to the point where my choices are not based around it.
I'm at a point in my life where I can essentially go on autopilot when shopping for groceries and not worry about the cost. I still have to make other decisions based on money (do I take a vacation or upgrade my laptop?), but the side effect of those choices is NOT stress.
So there's some minimum income that everyone needs (and it's different between people) where they can "forget" about living expenses and still have a relatively stress-free life. I'd wager somewhere around 1.5x - 2x the cost of living.
I take into account volatility of future income in order to be stress free. Hence my goal was to own businesses where my labor wasn’t needed to keep the income flowing in case I get injured.
Dual income household where each person earns enough to cover expenses can serve a similar purpose.
There is a sad, almost Catch-22 in the typical U.S. city where you need a car to make money and need money to buy a car.
When I was unable to afford a car though I was able to find a (minimum wage) job and a place (well, room) to rent within a reasonable bicycle ride. (Yay, I did have a bicycle still from my high school days!) I did succeed though (was even able to begin college at a small community college — rode to my classes via bicycle).
The first thing I bought though after food, rent, tuition and books was a rust-bucket of a car so that I had more choices in employment. (Sucks that gas, repairs, insurance, and registration then ate even more of my paycheck, but that's another rant.)
To be sure, I still now experience discontent, anxiety, stress and other things in life even though money is no longer making my choices for me. But, yeah, money is not the one calling the shots.
It's easy to in fact look back on those impoverished times and feel like they were somehow less stressful, and I felt less anxiety and discontent then than I have in the decades following. I'm not sure if that's the big lie we tell ourselves or if instead it is correct: either because money then was such an overarching issue that all other issues had to "get in line", or because when life boiled down to work-school-rent there really were no other 2nd-order "Maslowian" needs that I could be bothered to trifle with.
Most of my choices, and certainly all of my major life choices (like where to live, what car to drive, what job to take) are still based around money.
Edit: good points in the responses. I don't worry about eating out, what to order, what brand of sundry to buy. I do try to optimize but as others have said, that's more of a desire than a requirement.
Having said that, I think the only people who truly never worry about money are children. I've heard stories about international students at universities whose parents buy them luxury car after luxury car when they crash them, that kind of thing. But I suspect it's pretty rare.
For example, I no longer scour the grocery store for the cheapest available option for every item I select. I no longer have to spend months finding the best value for a pair of shoes, a piece of furniture, etc.
Basically, if I spend a couple hundred dollars too much on stuff one month, I'll hardly notice it. Whereas, when I was poor, that was the difference between making rent or not.
I played cautiously knowing that an injury could upend my family and my little sister’s future, and I didn’t partake in school sports or anything that could disturb my parents as they were already busy working 24/7 and it would have stressed them even more to have to pick me up or pay for equipment.
Money is important if you either don't have enough to meet your basic needs or have so much that you don't have to worry about it 1 second in your life (99.9% of people won't reach that state). Every steps in between is the same with extra distractions that won't do much, if anything at all, for you overall happiness.
Where you might not get to go to the doctor no matter how you feel daily, and you might have to walk to work because you can't afford a tire. I'm still happy to have hot water simply because I couldn't afford it for some years.
Life is so much less stressful when you have money leftover at the end of the month - enough to cover small emergencies and keep a $25 expense from ballooning into having electricity disconnected.
Granted, I think they've proven that after a certain point, money has diminishing effects on happiness, but I think it is mostly that you simply that it consumes your life less and less and gives you the means to think about other, more positive things than how to afford new shoes.
There's things other than lifestyle creep. For example, many families tend to increase their income as they get older. But the expenses also go up. Having one kid, vs 2 - 3 later on, or kid expenses when they are young vs. teenage years (where you now have to worry about increased car insurance, getting them vehicles, etc). And upgrading housing as the family grows. The effect is that your income constantly seems to be outpaced by increasing and recurring expenses.
So what happens is parents get into the mindset of doing without, so their kids can thrive. And when problems come up, they will sacrifice so that additional money can be thrown at fixing those problems. This doesn't let up until the kids are grown, and then you can sell the house and downsize. All of a sudden, your cars are paid off, the kids are doing good on their own (or you've disowned them), your housing costs is lower because you moved to a smaller house, which means utility bills are smaller too. This is now the point where people hit midlife crisis, they have surplus money and have pent up demand to "treat themselves" so go out and buy something expensive (sports car, motor home, boat, etc). And the tightened budget stress starts all over again.
I also reflect that the most significant choices are those which are within one's locus of control, the awareness of that is foundational to a life of virtue and money never seems un-constraining even if objectively one controls more of it.