Don't have a safety deposit box with precious metals and jewels inside?
Many, many people do - among other items (guns, cash, drugs, etc).
While "brick and mortar" banks may not exist, something of the same nature will - some kind of high-security place to store stuff like that, away from home. Maybe it will also be combined with some kind of networked backup storage for data as well...
To an extent, places like this do exist - private vault companies; always have.
I guess my point is that physical banks offer other services which can't be replicated virtually.
https://www.nytimes.com/2019/07/19/business/safe-deposit-box...
Give this a try, go open and put some rock in your safe deposit box, then call the bank and tell them you placed a C4 explosive in the box and will detonate it if they dont deposit gold under a park-bench in 2 days time.
Then watch how safe your safety deposit box is.
I live in backwards South Africa, and even I can't remember the last time I needed to use cash. So I'm totally with you on that one.
But bankless? Eh, I think we are at least two or tree decades away from that.
I moved to London last year and have used cash roughly zero times since. Visiting my parents (outside London) is like jumping in to treacle. Finding coins for the bus? Paper tickets on the train? Give me a god damn break. Even using chip and pin is weird now since almost all my purchases, except for dining out, are either touchless, online, or via mobile app.
In 20 years i think cash (banknotes, coinage), and maybe even bank accounts as we know them today, will be an almost alien concept to kids. Brick and mortar banks will be gone entirely. I certainly haven't set foot in one over a decade.