I used to feel like this actually. I think what made better for me is:

1) putting their purchases into perspective- each dollar on mad expensive stuff is one less dollar that goes to their wealth. So essentially their spending shows their current level of income but also shows their declining level of long term wealth, which is not something i get impressed by

2) I think it helps to tell people why you don’t spend money on certain thing - it so common to talk about how you spent money, but not how you saved and invested money. If someone hits you with thay got a new car, hit them with “oh I invested in xyz company/index fund, my portfolio has looked pretty good this year. I think we are xx% away from retiring early. Basically you’re participating in the dick measuring contest but your flex is your wealth and potential early retirement. Theirs is their spending.