I still laugh at the outrage from fellow workers when I showed up at my manufacturing job in some sort of “Nike” sneakers bought cheap at a garage sale.
They were appalled that I would wear them as just casual shoes, at a job that guaranteed they would become filthy with fiberglass and carbon fiber residue.
Shoes are just covers for our feet, I never buy them new.
I buy most of my clothes in thrift stores. When I'm done with them they are not even good for Goodwill, but they make dandy rags.
However, there are a few things I won't buy used - shoes and underwear, for example.