Could you expand on that? Technological progress has been less about increasing the gross amount of stuff the rich consume than the type. And for most things the poor get that stuff too, just later. iPhones, better, safer, more fuel efficient cars, flat screen TVs, , healthcare innovations etc.

Rich people do have nicer stuff but to a surprising extent they just have different stuff. An awful lot of that is zero sum social status signalling, like living in a richer area, or drinking wine, not beer, or gritting your teeth and congratulating your colleague on their kid getting into Princeton, when yours got into Duke.

I'd actually be really surprised if consumption inequality hasn't gone down since the fifties for most physical goods and services.