There are a lot of things outside of technical issues that can go wrong - here's an example: https://www.reddit.com/r/CoinBase/comments/6hcu0n/coinbase_cuba_law

There are a lot of things outside of technical issues that can go wrong - here's an example: https://www.reddit.com/r/CoinBase/comments/6hcu0n/coinbase_cuba_lawsuit/ https://www.reddit.com/r/CoinBase/comments/6hcu0n/coinbase_c... If you have control over your own keys (such as in the case of the "old" Coinbase vault) those things are a non-issue. But with the way how the new vault works a hardware wallet looks like a better solution.