You're only talk about your idea, but you still not really understand about proof of reserves. The concern about proof of reserves is the data isn't real time, so your idea will not work. We should also need to think about the collateral, since you're use blockchain, the collateral must be cryptocurrency or fiat since it's liquid. It's impossible if we talk about lending where you receive crypto and give your other crypto as a collateral.
But not possible if you trade for goods or service.
Concerns About Proof of Reserves (PoR)
Although proof of reserves offers assurance that a crypto company has the assets in place to cover its liabilities, it is only a single snapshot in time, not a live accounting of balances over time. It also only shows the on-chain assets of the custodian; it does not track where those assets come from (i.e., whether the assets were borrowed for the purposes of the audit).
What assets can be considered reserves?
Assets that are considered reserves are cryptocurrencies (or other types of assets) that offer strong liquidity. In other words, the company could sell off the assets to cover withdrawals or other liabilities, if needed. These may include cash or other fixed income assets. As for cryptocurrencies, this would include the more popular coins, such as Bitcoin and Ethereum, and stablecoins, like Tether, USDC, or BUSD.
In the same article you quoted under KEY TAKEAWAYS it also states that "a real-time track of reserves" is something that could be made available to users.
I just checked your post history, and it seems one of your projects still relies on having somebody help filter out bad actors. I don't think it is that different from how escrow works in a marketplace. If you plan to solve the necessity of an escrow then you need to build a tool that is smart enough, easy to understand for everyone, and not prone to false alarms so that it can solve any issues from both sides. I'm not sure if removing human intervention is the only solution since contexts do matter and a code might not be able to handle it. CMIIW.
Yes the marketplace operator would help filter out bad actors from even being able to list in the first place and being an arbitrator should disputes arise. A robust feedback system would be used to filter out bad actors. Users of the marketplace are incentivized to keep excellent feedback reports for their account if they want to keep using the marketplace and deal with other highly rated users.
