I have a lot of the same motivations — I have plenty of money, could buy anything I want brand new within reason. Yet almost everything I own is secondhand — my phone, laptop, tv, clothes, car, cookware, records, guitar, furniture, picture frames, headphones, camera. I’m not even particularly environmentally conscientious or frugal compared to my peers. For me it’s bit of sustainability, a lot of being frustrated at how much waste comes from new things, a good bit of “good god why are new literally cut every corner”, and a lot of fuck capitalism and this consumerist bullshit.