So, we either need to redefine the ranger as not being about survival in the wilderness, or we need to give something GREATER than finding food and water while not getting lost in the woods. And some of this may be found in world design, maybe the border regions between nature and civilization are safe enough for anyone, but the deep parts become far more deadly. Not in terms of "and here be literal dragons" but maybe the deepest parts of the jungles are so filled with spores and pollen that it is actively toxic to everyone, and will cause levels of exhaustion to anyone who spends at least four hours there, but also taking a long rest causes issues with the sheer number of insects in the deep mulch of the jungle floor. But, the 10th level ranger can get rid of a level of exhaustion with a short rest and climb trees with ease, and so they have the innate skills and abilities to deal with this environment.
And I know I'm starting to get into specifics, but the idea is what if we look to Ranger abilities to guide what exists, and increase the danger of things that exist, to guide what ranger abilities should be. If we start saying that environmental challenges should focus on causing exhaustion amongst the party, then the ranger being immune to exhaustion and able to more easily remove or prevent exhaustion suddenly becomes a viable angle of attack (noting that I prefer the One DnD exhaustion penalties)