In the middle class and upward, it's not common, outside of folks who are particularly frugal. The post-WWII American culture is extremely consumerist / materialistic.
It's also that it's just easier to go to Walmart or Target (or Amazon) and buy one and be done with it, than to spend the time hunting around garage sales or thrift stores for something they might not have. Unless you really need to save $10, time is way more valuable than money.
Of course, for immediate-need purchases, nothing beats going to the nearby store or ordering with delivery. But that's not how you handle getting second-hand stuff.
Second-hand stuff is easy to get when you know you need something (or will need it soon), but you're not pressed for time. At any given time, if you look for a second-hand $foo, you may not find it in your area, but there's a good chance you'll find it within a month or two. It's particularly easy with kid stuff - you have ~8 months of advance warning, and most kid items are only used for couple of months, so there's a steady stream of used stuff you can pick from, and a year later, start contributing to, as your kid grows out of their stuff.
What makes second-hand (especially free second-hand) so easy these days is Internet. To start, you want to find and follow three boards for your area: a) Craigslist/Gumtree/equivalent, b) a local giveaway/exchange group, and c) a local "spotted by the side of a trashcan" group. Put stuff you don't need on them, take stuff you need from them, and you're now part of the "reduce, reuse" flow - which is strictly better than "recycle". It doesn't take much time either; following b) and c) is something you do by scrolling through a feed for a minute.
According to Norwegian consumer research, people who save those ten dollars usually spend them on something else (like a travel or another product), so the environmental gain from buying used stuff is not a lot.
Unless people are willing to earn a little less, buttons used is not a solution for an individual’s environmental footprint.
My experience is different. Almost everyone we know gets most of their baby stuff secondhand. They get a bunch of stuff when the baby is born, from older friends with kids. Then they get specific items off NextDoor/Facebook/Craigslist.
I don't know that we'd get a potty used, but we did get used infant bathtubs, which is about the same from a hygienic perspective.
I agree. All of our friends and us get "kids stuff", as well as most of my furniture 2nd hand. My kids are 12 and 14, and outside of certain shoes, they've never worn brand new clothes (same for me and my spouse when we were kids). Why buy when your friends or siblings with older or bigger kids are looking to get rid of clothes as soon as their kids outgrow them? Come to think of it, I don't remember the last time I bought new clothes myself.
