Marketplaces thrive on liquidity and trust. The two seem to go against each other on the surface.
The more liquidity the more people, the more bad actors, the harder to maintain trust in general.
The safer you want it to be, the more trust you need between parties, the less people you can allow, which comes with reduced liquidity, unless everyone is trusting one entity which comes with its own downfall when those become parasitic middle-men.
Nostr is the solution to this problem. The more apps you are using, the more connections you can examine, the easier it is to introduce parties.
A high level of Liquidity can be achieved while trust is not eroded in the market.