Is there a way to buy cryptocurrency (particularly stablecoins such as DAI) with fiat money without using centralized exchanges or centralized parties (such as arbitrators, mediators, watchers) that is secure?

Something like LocalBitcoins but without needing a 3rd party when there is a dispute. The reason I ask is that even with these non-custodial peer to peer marketplaces, there is still a central point of failure that would bring down the entire market if it goes off line. For example, if the mediators fail to respond on Bisq, Bisq stops working in cases of disputes.