I think this is selling the idea a bit short. Fighters are generalists that are deadly all around, but one of the few consistent themes that has managed to stick throughout the editions is that the Ranger is a specialist that can take down a specific type of creature better than anyone else. There has been an effort to diminish this for reasons that everyone here can infer, however.I...don't know about that. I mean, I like the "Slayer of Beasts" role of the Ranger, but saying that no one else can do it? Dr. Rudolph van Richten has faced many monsters in his day, and he was a Rogue (well, Thief in the original setting).
There's no reason a Dex-based Fighter can't be stealthy with the right background. And Druids have plenty of divination and elemental powers already, and they despise aberrations.