Same here, I bought my current smartphone, a Pixel 6, two or three years ago for 200 dollars on eBay, and it arrived in pristine condition. Super small bump on one of the frame edges, not a single scratch on the display though now there are many, of course, I'm not that careful and the phone is cheap enough not to be too upset.

I generally trust private sellers a lot more than professional ones, if you vet them well enough (check their page, check their reviews, check their other listings), the chance that you'll get a good deal on a device in the condition described. The incentive to gain a profit is a whole lot lower, a commercial seller has to make sure they're the winner in some way during a transaction, they have bills, staff and assets. A private person is often happy to just get rid of the phone, as it would usually rot in the old phone drawer, until it eventually ends up in an e-waste bin a decade later when they clean out. Getting a little money back is already a win. Surprisingly, I've never had a bad experience. I presume there's also buyer protection, but I'm hoping I never have to use it.