When we say P2P, it doesn't automatically mean that it's decentralized. Many of us are still confused with this.
I think it's a matter of preference. Some traders probably refers decentralized when they don't have to store KYC and stuff like that when they use the platform. It's not entirely wrong imo, as long as both parties understand what they're trying to do.
It's still wrong and people who think it's the same are still misinformed or uninformed. P2P platforms allows trade between two parties without the exchange interference but that doesn't qualify them as decentralized when their servers are centralized.
These traders who refers an exchange not storing personal information for KYC as DEX probably thinks Yobit as decentralized too hehe.
And Decentralized exchange can also work as peer-to-peer platform. I believe that is the best way to go about peer-to-peer trading Bitcoin/cryptocurrency. That will allow for selfcustody, running of nodes, privacy, decentralized regulation, censorship resistant etc