The phrase ‘the Internet never forgets’ is complete bollocks
Remember, the web isn't about control. If a visitor to your site is familiar with using a browser's native form doodad, you won't be doing them any favors if you override the browser functionality with your own widget, even if you think your widget looks better.
The best way to be future-friendly is to be backwards compatible.
Mobile didn't create more unknowns for web designers. It just forced us to recognize the unknowns that were already there.
