I really like the development of subclasses that defy original class stereotype tropes but still fit into the broader narrative of the class. Examples – Path of the Zealot Barbarian gives a largely Cleric/Paladin style Divine flavor while Barbarians normally have more in common with Rangers and Druids. And there's also room for the explicitely non-magical Barbarian with more in common with Fighters than anything else.
We see similar developments like the Oath of the Ancients, Oath of the Noble Genies, and Oath of the Spellguard Paladin, which take the idea of the Paladin – defending/fighting for a noble cause specifically attached to their personal belief system – but show how this idea doesn't have to be explicitely "Fighter+Cleric." They're still Divine Spellcasters, but enough of a flavor splash from other power sources and theming tropes allows us to build characters that Smite in the name of an Archfey or Genie Prince or in the name of the Aes Sedai wizard they're bound to.
I also really like that despite these broad-tent classes, they still maintain a singular class identity. I can clearly tell the difference between an Artificer (of any stripe), a Path of Wild Magic Barbarian, a College of Valor Bard, an Arcana Domain Protector Cleric, a Knowledge Domain Protector Cleric, an Arcane Archer Fighter, an Eldritch Knight Fighter, a Rune Knight Fighter, a Tattooed Warrior Monk, a Warrior of the Mystic Arts Monk, a Spellguard Paladin, an Arcane Trickster Rogue, a Hexblade Warlock, a non-Hexblade Pact of the Blade Warlock, and a Bladesinger Wizard. And yes, the Arcane Archer, Eldritch Knight, and Rune Knight all feel distinctly Fightery too while distinct in their own ways from each other.
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I'd note that the Magic Stealer Rogue is an outlier to this pattern for me, and why I dislike it for essentially being a revised Arcane Trickster.
One other thing I dislike is the lack of robust systems built into the core rules to replace non-subclass features. This especially goes for spellcasting, and especially as the game becomes increasingly reliant on spellcasting to provide most features that might have been called a "spell-like ability" in past editions.
I do think I can adequately create a Martial Ranger through background, feat, and subclass choice for either Fighter or Rogue, but this closes off this concept from having its own proliferation of subclasses, let alone from accessing the on-brand subclasses that already exist for Ranger. Example – Monster Slayer Ranger archetype would work great for an Abraham Van Hellsing esque Vamprie Hunter without spellcasting but using magical-themed esotheric abilities to defeat Dracula.
I think the 5e system is flexible enough to create such a class through homebrew (Level Up is proof of that), but I find that sacrifices the distinct flavor of the separate classes that I love in the earlier part of my post here.