Because now, I'm not beholden to existing spells. Just like the Barbarian isn't required to use existing spells in order to fly or grant advantage to allies. With option 3, the sky is the limit. You can create completely unique effects that are specific to the ranger class.
It's very much the route of the Battlemaster for rangers.
Look, again, no one is wanting to take away the baseline ranger, I don't think. What is wanted is the OPTION of a non-specific spell casting (not necessarily no magic, but, a non-caster) ranger for their games.
It's not like it doesn't already exist. The Barbarian and the Battlemaster from the PHB work this way. Artificers aren't all that far off considering how few spells an artificer actually gets. A Battlesmith Artificer makes a pretty good template for a ranger.
Something that I haven't seen talked about in this thread is that a ranger is the fighter class with a pet. Having that animal companion is a pretty strong archetype for rangers - from Drizz't to Beastmaster. And the pet can be a major source of elements that you can use your spell casting slots for. Having your pet Enlarge for a few rounds, for example, isn't a huge deal (call it Rage or some such). There's a boatload of things you could do to tie the ranger to its pet.