Agreed.
Going strictly off the PHB as otherwise 'core' gets too hard to define:
1e: Cleric, Druid, Fighter, Paladin, Ranger, Magic-User, Illusionist, Thief, Assassin, Monk, Bard.
2e: Cleric, Druid, Fighter, Paladin, Ranger, Wizard (includes Illusionist as a specialty), Rogue, Bard.
3e: Cleric, Druid, Fighter, Barbarian, Paladin, Ranger, Wizard, Sorcerer, Rogue, Monk, Bard.
4e: Cleric, Fighter, Warlord, Ranger, Paladin, Rogue, Wizard, Warlock.
5e: Cleric, Druid, Fighter, Barbarian, Paladin, Ranger, Wizard, Sorcerer, Warlock, Rogue, Monk, Bard.
Of the 12 classes in the 5e PHB, 9 were in the 1e PHB 36 years earlier. And note that 'missing' classes often showed up in supplements.