Earlier quoted context omitted.
1) No counterparty risk. Everyone can get hacked, but coinbase being hacked shouldn't every, under any circumstances result in me loosing any bitcoin they hold on my behalf. This point may prove to be very sticky. It might be solvable with smart contracts... consider ethereum's https://www.etherdelta.com , which operates as an auditable smart contract. Your money literally can't be stolen without your private key; ev…
This is what insurance is for. If they can’t insure deposits, then that shows a fundamental weakness in the security model.
(Admittedly the website is housed somewhere, but it's little more than a GUI shell for signing procedure calls, you could run it locally or interact directly).
I think the big issue hindering that model is that they need something allowing users to pipe into traditional currencies. So far all the solutions to that have been IOU tokens like USDT tethers; which end up generating governance headaches of their own, as their value desyncs from their base currency due to arbitrage & supply issues.