Luxury used to be having money to buy things. It was the accumulation of wealth.
In the modern aspiration economy, luxury is having the taste to know what things to buy. It is the accumulation of social and cultural capital.
At the same time, we should remind ourselves that no amount of cultural capital can subsidize financial freedom. The #1 factor in determining inequality is still access to money. It doesn’t matter how many novels you’ve read or how “tuned in” you are.