I'm trying to understand where you are coming from with your responses to
@FitzTheRuke. What I think he is saying is the following. I have a character concept and the background for my PC that he was a clam diver on the coast of Amn and his brother was killed in a sahuagin raid. That got him into adventuring to get revenge. He's going to be a paladin of vengeance. Going through the list of 2014 backgrounds(since I don't have a 2024 list) I don't see a single background that is close to Clam Diver, and I can guarantee you that you won't see it in 2024, either!
That means that I have to create my own background. So I make Clam Diver and assign +2 Con, +1 Dex, because swimming and clam diving would involve both heavily, but I think Con more. For the feature I double the length of time my PC can hold his breath and since that's very niche, add in that he gets advantage to his rolls to scrounge up food when near water features. Lastly I give him athletics(for the swimming) and Perception(hard to see and need to spot quickly underwater) as the background skills.
The above is something that any DM should just grant without any moaning or groaning. As he should grant any reasonable background made by a player. There are thousands, if not tens of thousands of distinct backgrounds that should be available to players in character creation, but which the designers don't have the time to make and the book doesn't have space for. There should be no difference between official and home brew here other than official takes less effort.
That leads me to what I think
@FitzTheRuke's point is. The world should be reacting to that background every bit as much as soldier or hermit. If it doesn't, that really is "A DM not worth their salt."
I mean, I think all that stuff TOO, but the only thing I was trying to talk about is that the 2024 example Backgrounds can be taken, but you can take a different Feat, or a different ASI, or a different set of skills, or change anything about it really.
I mean,
I'd prefer it if the things you choose still seem to fit the name you choose (or in the very least, that you have a story-reason as to why YOUR version is vastly different) BUT you don't even need to do THAT. For example, the playtest "Acolyte" gives you:
Ability Scores: +2 Wisdom, +1 Intelligence
Skill Proficiencies: Insight, Religion
Tool Proficiency: Calligrapher’s Supplies
Language: Celestial
Feat: Magic Initiate (Divine)
But if you were making, say, a Duergar Acolyte Champion Fighter, you could conceivably make it:
Ability Scores: +2 Strength, +1 Wisdom
Skill Proficiencies: Perception, Stealth
Tool Proficiency: Mason's Tools
Language: Undercommon
Feat: Tough
I'm not sure why you'd pick "Acolyte" if you wanted to change it by THAT MUCH, but you COULD. If I were your DM, I'd hope that you'd come up with some Duergar Acolyte organization (I'd help you) to excuse all those choices.
Now, I mean this to be an extreme example. I'd rather you called the above choices a "Guard" or a "Pit Fighter" or something more appropriate to the choices, but if you wanted it to be Acolyte? It would still work by the rules. I think it's a feature, not a flaw, for the game to not enforce that sort of thing. Your DM can do it, if it needs doing.
Obviously, the simpler (and more appropriate) part of my discussion was the idea that, for example, some people are looking at the playtest "Acolyte" and complaining "What if I want +1 Charisma" instead, or an Acolyte that doesn't know Magic Initiate but is a Medic instead (much more reasonable than my extreme example). You can DO that.
The WORST arguement I've heard is "So all Farmers are Halflings now!" (Because the example Farmer background's language is Halfling). It's just an example! Pick goblin if you want it. Or whatever.