That's my (limited) understanding. Gives a large chunk of money an officially-plausible source. But I haven't really studied the topic.
Something else to consider is that the seller profile may have been hijacked. People leave an account dormant and don't check it often or at all may have no clue that someone else is using their account and good feedback to pull off a few scams.
Pretty much these days I don't buy much unless it is one of my saved, tried and true sellers. If they aren't fake, then many people (including unscrupulous sellers) post deceptive washed out photos hiding hairlines and cleanings. Every once in a while a legitimate seller liquidating their collection comes along, and I make exceptions.....knowing I might still get the shaft. Risk vs reward, it still has it's place in collecting online.