Trust is involved in one way or another. Marmot just moves that trust almost all the way to the clients. And very few well-intentioned.apps can even implement the thing property. Hard to interop, easy to mess things up on the none-Marmot aspects (multi-device, key package sharing, etc...), ... Al...

And nostr:npub16p8v7varqwjes5hak6q7mz6pygqm4pwc6gve4mrned3xs8tz42gq7kfhdw keeps bringing up the good point that for business comms (regarding disputes etc...) you NEED signatures.