So back in the day prior to subclasses I started a thread entitled strip background out of class. I think this is just as relevant today, though I think stripping background out of subclass is the important one now. This has been hit before in threads but I think it needs to be called out in its own thread.
So, backgrounds are an excellent addition to the game, you can be all kinds of backgrounds that add a layer to your character that I think is very cool. With the advent of subclasses though some of the background stuff is being sucked back into the subclasses. I would like sublasses to be independent of setting and more focused on the how than the why. Then let the backgrounds subsume the why. A couple of examples: the knight, this should be renamed to something else, knight should be a background and have nothing to do with a subclass. Call it the defender or anything else sufficiently generic. Now for casters I think this is a little different the how you get your magic (domain, pact, bloodline, study) should be your subclass, then you can apply a background that is of your devising.
So who agrees with this approach?
I have no idea... One year ago Backgrounds were a major part of 5e, we had this Race+Class+Background+Specialty setup and I think it was fine, a lot of people liked this structure. There has always been discussion on what Background means in narrative terms, WotC designers intended it mostly as "what you were before picking up the adventuring life", personally I preferred the "what you are when not adventuring (and how you make your living)" (which IMO fit very well with the mechanic), but both basically represent you
role in society. However there were people wanting race or type of society (most commonly barbarian) to be represented by Background, so that some backgrounds would represent your whole society of origin instead of your role in it.
Either way, currently Backgrounds are very-slightly less important than before when skills were mandatory and Backgrounds were the main source of skills. Lores are mandatory but IMHO they tend to be ignored by some players, at least in the sense that tends to be used less proactively than physical skills. Proficiencies are more interesting, but you really get very few from Backgrounds.
IMHO the real reason for introducing backgrounds into the game was not really because the game needed a mechanic to represent your "life before adventuring" or "life when not adventuring". Narratively, it could always be done by those who wish, no rules needed, and only a few players really need mechanical benefits (don't get mislead by how many people say they love Backgrounds with mechanical benefits... of course almost all of us like such system once you have it, but before we had it only a minority of groups even thought they needed one). Instead, IMHO the Backgrounds were introduced mostly as a "delivery mechanic for skills" to allow more freedom in character creation (because unlike 3e it wasn't hard to get skills unusual for your class), inluding some options for "slight multiclassing" (e.g. nobody's playing a Rogue so I'll be a Fighter or Wizard or else with Thief background and I can disable traps).
Now they are a "delivery mechanic for lores and non-weapon proficiencies" but class also gives them, while OTOH subclasses have become one of the most important delivery method for both narrative and mechanical features, and also to dial character complexity... I think the problem you're pointing out is very real, but I am afraid it's starting to be late for re-thinking everything again. Overall, the edition is steered by wanting to be as inclusive as possible, so we have different cases of methods which overlap in terms of what they represent narratively and what they deliver mechanically...
