> If you're using macOS Monterey or later on a Mac with Apple silicon or a Mac with the Apple T2 Security Chip, use Erase All Content and Settings instead of the remaining steps in this article.
So, it is literally a two step process for any Mac released since the end of 2017, and the first step is just an optional reminder to cancel or transfer your AppleCare coverage if you have any.
So, one real step. Wow, so hard.
> assuming that the seller is even aware
The buyer should make the seller aware of the problem, because it is in the buyer's interest not to end up with scrap.
But, regardless, why would the seller not want to wipe their computer first? The seller will inevitably hit the button mentioned in the help article simply because that's the only obvious way to wipe the computer to anyone who isn't super technical. This is a problem that practically solves itself for devices that aren't stolen.