RoboSats is what is known as a P2P exchange, but they are unique.
Some P2P exchanges (e.g., Paxful) require identity verification. RoboSats does not.
Even some P2P exchanges that do not require identity do hold custody of your funds (e.g., AgoraDesk). RoboSats does not.
Of the very small list of P2P exchanges that do not require verification and are non-custodial (HodlHodl, Bisq, LocalCoinSwap, and RoboSats), only RoboSats uses lightning network as the trading currency.
Financial privacy is so important with RoboSats, you can't even use a regular browser (e.g., Chrome) and you don't even get to set your username -- you are assigned a new "robot" for each trade.
Even some P2P exchanges that do not require identity do hold custody of your funds (e.g., AgoraDesk). RoboSats does not.