That definition of wealth is all well and good for books about how markets are magical fix-everything pixie dust
No, it actually means something. We have access to refrigeration, climate control, near-limitless computation, entertainment, transportation, knowledge, communication, and medicine. All of this stuff would BLOW THE MINDS of medieval kings. Even if you're living in a 1BR apartment, working at Walmart and struggling to pay rent, you enjoy many luxuries Charlemagne could scarcely dream of.
Go to the store, grab a pineapple off the shelf, take it home, and eat it. Then read about the great lengths [1] the wealthy people of the past went to in order to try to grow pineapples in Europe, and how obsessed the culture became with this fruit.
If you're in that one bedroom, struggling at Walmart, you probably don't have a dishwasher or a washing machine and dryer, and possibly not air conditioning or heating, or at least, your electricity bill is enough that you have to think twice before setting climate control to a comfortable level. Your social life probably isn't anywhere near what Charlemagne had. You have a smartphone and that has brought you news from afar. But that news is terrible! Local politics, things are fucked, climate change is out of control, geopolitics is a whole other shit show. Charlemagne didn't have to deal with Israel and Donald Trump. His world was very different. Sure, I have a fridge and a microwave and can use that to sate my hunger in mere minutes, a luxury inconceivable to Charlemagne, but all the trappings of modern society, with TikTok and Reels hasn't made us globally happier. Seeing the emotional damage from whichever online platform surfaces drone videos out of Ukraine today for me as a form of wealth is one perspective. We've lost the plot, or at least I have. We're solving the problems in front of our faces without asking if that's the right problem to be solved.