Sure, there's often going to be some centralized source one needs to trust. The issue with a digital escrow vendor is kind of like the issue with cryptocurrency exchanges - one single breach and you immediately walk out with an unfathomably huge treasure trove.
A rogue notary employee can do some damage and notarize things in exchange for bribes, and a rogue bank employee could help siphon some money away, but a rogue digital escrow employee could be bribed to hand over terabytes of extremely sensitive data on lots of big customers, and a rogue cryptocurrency exchange employee could possibly help someone steal hundreds of millions of dollars pretty easily. It's a huge house of cards.
