A fair point, although photos provided on the site, as well as seller reputation can (and mostly the latter on darknet sites, but both are useful) address that issue. What's more, an escrow system that requires the buyer to confirm receipt and quality for the seller to receive payment could have an even stronger impact on such issues.

>Also customer tend to game that to get free products which makers hate.

Which is why darknet sites have dispute resolution policies and processes, as well as ratings of sellers and buyers. Those buyers who try to take advantage are shunned pretty quickly as bad actors and unprofitable to boot.

You can't game a system that won't play with you.

I suggest you check out some darknet markets[0] -- not to purchase anything that might raise the hackles of your local government, but rather to see how a marketplace which doesn't have the sanction of law/government/the courts tries to ensure fairness and minimize rip offs and bad actors.

If you do, I think you'll find that many of the tools used in those environments would improve user satisfaction (on both sides) and create a much better marketplace. Even a "legitimate" marketplace like Etsy.

Edit: fixed grammar, added references.

[0] https://darknetmarketlist.com/darknet-market-list/ [1]

[1] Some of the listed markets have been seized/exit scammed/otherwise offline. As the old saw goes, 'caveat emptor'.