define P2W. What do you win? There was zero competition in D3 vanilla.
You just grinded for items for the sake of grinding items. The auction
house was a mistake because it made trading too easy and too valuable.
That doesn't mean that trading is the root of all evil and has to be
eliminated. It's a design choice.
Diablo 2 and Path of Exile were build around trading. For both games, you can buy items for money on third party sites.
It will always happen as long as you can give valuable things in game to another player.
If the developer sells the best gear for money, it's p2w. Most players agree and don't like that.
If third party sites do that, and some of the stuff sold is stolen from hacked accounts, it doesn't make it less p2w.
Bagstone is right.