Class-wise, I'd like to see a Psionicist for Dark Sun. But I don't think any new
classes are needed if they're not revisiting Dark Sun -- and they've said they're not in the foreseeable future.
Beyond that, I'm not sure what adventurer archetypes are missing.
Usually, when I see people saying "archetypes" are missing, they have specific and unique mechanics in mind that used to exist and now do not.
For example, take Warlord. I'm not entirely sure why paladin or fighter or war cleric or valor bard don't fit that character archetype even with a custom subclass. Still, the usual response to that is "first-order lazy combat." The problem, though, is "lazy combat"
isn't a character archetype. It's just a unique mechanic. It's a mechanic that doesn't translate well outside of 4e, but that's somewhat beyond the thread's scope.
The point is that
mechanics are not what defines a character archetype.
When I think of character archetypes, they are not just a character class, but a character class plus a background and sometimes a species/race. That's how paladin can represent the classic white and black knight archetypes. That's how rogue can represent both thief and assassin archetypes. That's how artificer can represent both gearpunk and alchemist archetypes. Just as one mechanic does not define a class, class mechanics alone do not define a character, let alone an archetype.
For example, I'd consider these
archetypes or archetype elements totally missing:
- The monster with a heart of gold -- The closest I could come with this would be to reflavor a race as a monstrous creature, and then use monk or barbarian, but the trappings don't really work that well.
- The wealthy aristocrat -- Could be an actual landed noble or just a merchant who bought a title, which are common enough backgrounds, but D&D doesn't support starting with a bank account.
- The cursed wanderer -- Works best in solo games, sometimes, as otherwise the curse tends to kill the other PCs.
- The aged veteran or wizened sage -- Could be a mentor figure or something similar, but the game doesn't really support starting out with a high level of competency and then being surpassed by the other PCs or dying off or retiring before the end of the campaign. The game just isn't structured that way. These are NPC-only.
- The professional out-of-their-league -- From physicians to lawyers to scholars to smiths, these are the average characters who find themselves doing things they didn't plan on doing and haven't been training for, but that bring an entirely new set of abilities to the table. The game says they're not really adventuring types, so they aren't available to be adventurers. They're confined to NPCdom. Not weird enough or wild enough, I suppose.
The real issue is that every time they try to introduce something like the above, it's always watered down to toothlessness and forced to fit the rest of the game. You can be a monster with a heart of gold... by being a bugbear with a nasty scar. You can be a wealthy aristocrat... who is recently disinherited. You can't be an aged veteran... who is nevertheless just a level 1 PC. You can be a cursed wanderer... with a curse that makes you sad every few days and is otherwise all benefits and no actual dangers, costs, or hindrances. You can have a profession... as an also-ran to your main occupation as an adventurer.
In other words, I think mandatory class equity is the actual limiting factor for adding more
character archetypes to D&D. Yes, a common theme is that none of these archetypes fit into D&D's design, and several strain or outright break many of the preconceptions and premises of the whole game. But at the same time, I
can play these archetypes in other games, and they
are missing in D&D. In other words, they're missing archetypes, but they're not present because they're not what the game is interested in presenting.
On the other hand, if you're just trying to jazz-up saying, "I want more classes," or "I want more mechanical variety," that's fine. But I don't feel like it's appropriate to call those
archetypes.
I'll agree that subclasses are disappointing, and classes are pretty samey. Subclasses are not as defining or transformative as I'd like them to be. In many cases, they don't add as much to a class as they should. They all feel like they should feature a redefining central mechanic, and very few do that. However,
that's just fifth edition D&D. It's kinda dull, uninspiring, and
safe. I don't see that changing. Not until I'm too dead to be playing this game anymore, at least.