I'd like to point out, Minigiant: It's not about -names- exactly, or nomenclature. It's about identity and impact on culture and narrative.
Wizards matter in the narrative. Not just as a specific name, but a specific identity. The "Old Wizard in the Tower" or the "Teacher of Apprentices" is always clearly a Wizard character. The class fantasy is there, whether the character is called Wizard or not. Because having a spellbook and high intelligence are core details of being a Wizard.
Same thing with Fighter. Fighter as a word doesn't need to specifically refer to someone who gets Combat Maneuvers, Action Surges, and 4 attacks in a round. A Knight can represent a fighter. So can a General. Or a folk hero. Or a wandering swordsman. All of these concepts fit into the identity of "Fighter". In fact as an umbrella term, a -ton- of class identity is written into every world for them.
But Sorcerer has a very -specific- story to tell. One of magical lineage. And that story is almost never a part of a setting's narrative.
Similarly, Druids are often a bit lacking in representative fiction for a setting. Artificers. Rangers. Barbarians usually have at least one or two "Savage Tribes" which has it's own problems, obviously, but carries their fiction...
The general thrust is that the class identity should be a part of the world. That there should be exemplars of "This is what it means to be a Sorcerer" and a cultural identity to be carried with that. Whether a character holds themself to that or sets themself apart from it is a different question, but can help cement identity through negative inference. "I'm not like other sorcerers"