Right, all characters have the option for stat allocation, feats, and backgrounds, independent of class. Also, rogues have Thieves' Cant, which gives them a lens to view the worlds of D&D and implies a cultural context; a player choosing to play a rogue enjoys having that framework/lens as a point of reference. And so on for every class, excepting the fighter.I think bonus ASI/feats are mechanics to reinforce that backstory. As is the background selection. Possibly stat allocation, fighting style, and subclass options.
The fighter's PHB subclasses have no identity. Even Mike Mearls agreed with that sentiment. Xanathar's has started to open that up a little, but to a rather limited extent: Arcane Archer, Cavalier, Samurai.
Yeah, that opens up the question: Why is the fighter different that way than the wizard, cleric, rogue, etc? Should it be designed as a generic template? Is something about the fighter conceptually at odds with built-in identity that other classes receive?A dex fighter with a criminal or spy background has more room for feats like dungeon delver, observant, or skilled because of that class mechanic. That gives contacts via background as well.
Fighters are more like a generic template but I find that opens up concepts as opposed to restricting them.
Clearly, designers of past editions of the fighter didn't think so – "fighters as lords" was alive and well into AD&D 2e. A shift happened around 3rd edition (or rather, the slow shift became more dramatic and obvious at that time), stripping the fighter of that built-in identity in favor of the "generic template" model. It's fascinating, because AFAIK no other class in D&D has had such a central concept removed from it.