Mostly. I'm certain some of the stuff moved on secondary markets is stolen, and if the previous owner did their due diligence, it should be blacklisted by service providers by the device's unique ID.

There's also plenty that are 100% legit and you won't have any trouble whatsoever. I try to stay away from eBay for phones; I go to the local marketplaces, like FB marketplace, Kijiji or Craig's list and do the exchange in person. Being able to look someone in the eyes and ask them why they're getting rid of the phone, in and of itself, can weed out theives.... Not entirely, but mostly. You also get a clean cash transaction, you can look at the device and check it over to ensure it's what was described, get, and likely test any accessories, and do any last minute negotiation that might be required based on what you've found while handling the item.

It's not perfect.... But your only other option is to buy a refurb from a first party seller like your mobile provider, which will probably cost more, it will also likely be carrier locked... But you can rest easy that it wasn't stolen....

I switched to buying directly from manufacturers (in my case, Google) and just plugging in my carrier sim card. I've been happy with that. I also always run with a good case on my phone, usually spigen, and I haven't had any notable damage to my device as a result (which would require an early replacement).

YMMV. Good luck