Aside from ethanol's water absorption issue, the big problem is that gasoline and ethanol are very different. Gasoline is OK with some materials, and ethanol is good with others... but few non metallic materials are good with both ethanol and gasoline. Buna N rubber is good with gasoline, not so good with ethanol, while silicone is good with ethanol but bad for gasoline. Teflon is good for nearly anything, but it's expensive and not very strong or flexible by itself. Not just rubber hoses, too, but sealers like gasket shellac and pipe joint compound can be dissolved by ethanol... and the shellac on the fuel gauge cork of many older planes.

The ONLY people benefiting from ethanol contaminated fuels are corn farmers... and, of course, congresscritters in corn growing states.