Of course there is - archival quality printout of a paper (on archival acidfree paper) wallet stored in a bank safe.
That's safe. Convenience depends on how often you need it (and so there's not one standard of convenience you can quantify without being the actual person who's using it.)
The recommended place to store bitcoins, the currency which promises freedom from the corrupt banking system, are banks?
> That's safe.
It is quite safe, but still not as safe (World Trade Center, Hurricane Katrina, ...) as your money in an account with insurance. And much more inconvenient.
You can split a bitcoin key up using Shamir's Secret Sharing Scheme (or just multisig) and store the key geographically-distributed such that if any one location is destroyed you don't lose the money, and if any one location is stolen the thief doesn't get the money.
You can also replace "one" with an arbitrarily-large number, depending on how many locations you want to store the money in.
Now compare this to online banking and seriously tell me that this is easier. Yes, you can set up a system that is very resistant to failure. But my grandma doesn't understand the difference between minimizing a window and deleting her facebook account. I'm not excited about explaining SSS to her.
> Now compare this to online banking and seriously tell me that this is easier.
It's not. But compared to storing large amounts of dollars, pounds, or euros, it is easier.
> Yes, you can set up a system that is very resistant to failure. But my grandma doesn't understand the difference between minimizing a window and deleting her facebook account. I'm not excited about explaining SSS to her.
Your grandma won't need to know about any of that, because she'll probably continue to trust an organisation to look after her money for her.
Just because cryptocurrencies make it feasible for people to not trust other entities with their money doesn't mean that everyone will.
That's safe. Convenience depends on how often you need it (and so there's not one standard of convenience you can quantify without being the actual person who's using it.)