This isn't excessive abstraction - this is just different abstraction. Files and folders are a human invention, and there's no law of nature forcing us to continue using them. It's like complaining about people forgetting how to use MS-DOS commands, when Windows (until PowerShell) was built on GUIs through and through and MS-DOS commands were only still there for compatibility. You don't have to learn MS-DOS command to copy files, you learn to use Explorer to copy files (which to a small extent is like using the MS-DOS command).

Or like complaining people forgot how to use teletypes. We didn't have to keep using teletypes, and we didn't keep using them. Our Linux terminals are still modeled after teletypes, but not in a way that has anything to do with using a real teletype. You don't learn teletypes, you learn terminals (which to a medium extent are like teletypes).

It isn't like when people don't learn to add numbers or how Quicksort works or assembly code. Those are still fundamental truths that help people understand things. It's more like not learning to write Roman numerals, or not learning ALGOL 60. Nothing is really lost except the ability to read old things. You don't learn Roman numerals, you learn western Arabic numerals, and they're better, not worse. You don't learn ALGOL 60, you learn C11, and some people would argue whether it's better, but it's not worse.