It definitely is inherently cumbersome. You need a good backup system (think offsite), while putting all eggs in the basket of computer security. If someone hacks my bank account, I will be inconvenienced. If I had all that money in BTC at home, and someone gets the password, I lose all of it, with no recourse. If I lose access to my own password, it's all lost too. You can build your own recovery mechanisms, but those quickly become new attack vectors: Just ask anyone that has lost online accounts of any sort. With the difference being that there's nobody that will ever hand you access again,because you are not trusting any authority.

So any setup I would consider safe enough to hold mode than 10 thousand dollars worth of coin is one that is no simpler than an enterprise level security system. It's enormous overhead for any individual. And given how BTC is designed, it's absolutely impossible to delegate most of this work to a third party without opening yourself to more risk.

It's a bit like having your money under a mattress, with the difference being that someone can automate hacking into houses to search under the mattress.

And that doesn't even get into issues like accidents: You also need a backup plan on what to do if you die, or go into a coma. Does anyone get to recover your coins, or are they stuck forever in limbo? It's yet another thing you might want to deal with.

In the regular financial system, all of this stuff is handled for you. If you roll your own, you have to manually build all of this yourself, find who to trust with what... and every single protection you build is also a new attack vector. It sounds rather unsolvable to me.