Most layer 2s do right now. That is not how they are meant to be though. A true layer is completely non centralized. That is the whole point of the fraud proofs

Most layer 2s do right now. That is not how they are meant to be though. A true layer is completely non centralized. That is the whole point of the fraud proofs. The ideal end state is stage 2 described here https://ethereum-magicians.org/t/proposed-milestones-for-rollups-taking-off-training-wheels/11571 https://ethereum-magicians.org/t/proposed-milestones-for-rol...