I wish the "note taking app" crowd would think harder about that.
There is a great book about the early age of hype and how it failed, called "The Myth of the Paperless Office" [1]. Would be great to re-read it and see how it holds up.
By the way, there still is a market for hipster PDA gear and some companies seem to make quite a bit of profit with it - here are beautiful note taking index cards with additional gear (dividers, archival boxes and so on) [2]