Li Shenron
Legend
Why can't the ranger have a mixture of both?
Things like Pass without a Trace and Hide in Plain Sight could be something that isn't supernatural but just being "that good".
Healing, Camouflage, Cure Disease, See Invisibility, Glitterdust, etc could be done using herbs instead of spells.
In 3e we had a Ranger variant that did exactly that: we took many spells (not all) and turned them into extraordinary abilities, and a Ranger would choose which ones to learn (instead of spellcasting). Some of those are useful only sparingly, so it was ok to turn them into "at-will", which improved their believability as non-magical.
Favoured Enemy and Favoured Terrain are really missed opportunities that when done right can give the ranger some identity.
The problem with them is that if they are too good, then players start complaining when they are not in their favored terrain or not against their favored enemies. But you can't always set adventures in the desert fighting dragons or in swamps fighting orcs, it would be boring for everybody else... One idea that helps, is just to have many favored terrains/enemies, but not too many or they'll hardly be "favored" anymore. The other idea which the 5e designers got right, was to make the benefits more widely applicable than just with the actual favored enemy, but notice that this is not really named "favored enemy" now, instead it's under the Hunter's subclass features (the base class "favored enemy" benefits are more fluffy).