Collaborative 2of2 Multisig to Trade Goods?

What would be some drawbacks of doing a collab multisig with someone as a way to safely trade goods for BTC in order to protect the buyer. Even if a trusted mediator had to be included in some sort of 2/3 multisig to insure no bad acting comes into play during the transaction, wouldn’t this be a good way to help facilitate trades for people only wanting to deal in BTC? Would love some opinions from some intricate thinkers out there. Thanks.