To be solely relying on a smart contract to meet the transacting party agreement could become tricky. It also limitate only on what specific conditions could be designed within the smart contract as for the escrow.

I don't know if there are exists in-development or trustable decentralized escrow, at least it never get mainstream attention within the crypto space. I think the reason it never gets discussed is that it is only limited to a very specific condition, thus I believe it won't scale broadly.