In my opinion the 5e ranger is ok conceptually. It is the right place for a D&D ranger it is the implementation details that are the issue. That is why the ranger remains popular on DND beyond despite disssatisfaction.
I think the issues are:
The Bestmaster sucks
I think that Natural Explorer boosts should apply in all natural terrain, otherwise the ranger can be out performed in what they are supposed to be good at by scout focused Rogues and that wilderness exploration play is not a feature at many tables.
The ranger has a number of neat spells but they are all concentration and many are situational.
Finally the Ranger in a fight, while (IMHO) a solid contributor, is chipping away at the enemies and looking at some fighter builds and the paladin and feeling a bit jealous. Particularly after 4e where often an encounter with a ranger in the party was like: initiative, Ranger - hits every enemy does lots of damage...…. Warlord "Ranger do that again" …. Fight over.
I think the issues are:
The Bestmaster sucks
I think that Natural Explorer boosts should apply in all natural terrain, otherwise the ranger can be out performed in what they are supposed to be good at by scout focused Rogues and that wilderness exploration play is not a feature at many tables.
The ranger has a number of neat spells but they are all concentration and many are situational.
Finally the Ranger in a fight, while (IMHO) a solid contributor, is chipping away at the enemies and looking at some fighter builds and the paladin and feeling a bit jealous. Particularly after 4e where often an encounter with a ranger in the party was like: initiative, Ranger - hits every enemy does lots of damage...…. Warlord "Ranger do that again" …. Fight over.