Binance exchange got you covered, imagine if binance isn't the middle man, even a well rated trader can just decide to ruin you up one day, it will be like a country without the law, forget the rating side and focus more on how Binance handle it's p2p, I use binance a lot and I don't bother checking how many trades a trader has successfully complete, it doesn't matter, because on Binance you can't lose money in p2p, unless you mess things up yourself, like releasing fund before Fiat get into your bank account.