The idea seems quite interesting. I believe the reason we still need this is that smart contracts are too hard to be used in real life by ordinary people, right?
This one-way hold is an attempt to avoid using extra people who provide escrow, while ensuring safe shopping. Let's say the money is in the hold area and the buyer is waiting for the product to come. If the product doesn't come then the 'hold' is not released. Where does it go? Can it be withdrawn by the buyer? And what if the buyer is the scammer and attempts to get the product without paying for it? Who/what will decide who's right in such cases? Basically, that's what escrow is needed for. Trusted members are not just holders of the funds, but also the judges in cases of problems.
Could you explain how your project deals with such things?