I'm looking at it in a long-term perspective. As a comparison, to have to keep one's computer safe oneself is also incredibly old tech from that perspective. The usability of information technology will become much better. Even having to install apps on a smartphone is very old and cumbersome tech.
I guess you're a kind of a prophet, or there's something in your version of the future that hasn't made it into mine. I keep my own computer safe because no one else has a vested interest in keeping my computer safe like I do. When I buy a smartphone the first thing I do is erase everything in memory and install cyanogenmod---why? because I've inspected the source code and I can control what I put on or take off. Oftentimes, I download the cm source code and modify it to my needs before I put it on my phone. Who else is going to do that for me? I don't really know what you mean about "old and cumbersome tech". For me, it really sounds like you're saying something along these lines:
Having to choose what you are going to eat for dinner is very old and cumbersome tech. In a happy future, you can just allow a company or institution to choose your dinner according to a correctly balanced nutritional profile.
However, in my world, choosing what apps to install, what pictures to back up, what plants to put in my garden, what to eat for dinner isn't "old and cumbersome", it's what makes me me! I don't want to agree that choosing things for yourself is an old and cumbersome way to live.
How many people store money under the mattress today? Sure, storing money in the bank is also old-fashioned compared to the future. The trustless part of cryptocurrencies is a major step forward. But trusting oneself isn't trustlessness. That's why I consider having to manage security oneself will sooner or later become outdated.