It's a high cost thing for them. That's pretty much the extent of it. You might notice that businesses pushing costs down as much as they can has been a general trend for a few decades.

Also, with so much digitization that's occurred, assets tracked in electronic accounts, fewer and fewer people have need for a such a service anymore. Eg. In the late 20th century you can imagine somebody putting stock certificates in a safe deposit box. Why would you do that now?