Bisq 2 has both moderators and mediators. If a user is scammed then the seller's profile would be banned from Bisq and the associated reputation they built would be lost. As there is a cost to develop a reputation for sellers it is in their interest to act honestly during the trade process.

Bisq 1 has arbitration because the funds are deposits into the multi-sig by the buyer and seller prior to the trade taking place. This is not the case in Bisq Easy.