Btw seeing 5 Bitcoin move from one address to another proves nothing by itself. There's nothing on the blockchain that says "this proves it was for a house" or "this address belongs to the person selling me the house". Seller could simply say you didn't either: "Sorry, you mustve sent it to someone elses address by mistake. Tough luck."
Discussion
You just contradicted yourself saying transparency opens you to attack. How does an unrelated third party know who a wallet belongs to?
No I didn't. If you merely did what I said above you could easily be scammed. I would assume both parties are identifying themselves if they're making a transaction that large and getting contracts/lawyers/notaries (third parties) to confirm addresses to identities, but all that occurs off the blockchain.
Transparency does open you to attack. The difference is Monero is optionally transparent, only if you want it to be, and only for a specific transaction. Can't do much with just that. They still don't see your balances or who else you've transacted with. Bitcoin is always transparent and you're tying your identity to your history and future transactions that have nothing to do with those counterparties and third parties you're involving.