Okay, here's a point by point rebuttal.
1) Attribute bumps
The character doesn't really change. My strength is now 18 instead of 16. If I'm the "muscle" of the group, it's not like the roleplaying options are changing or people are all of a sudden going to perceive me differently. I'm still going to be essentially the exact same character, just attack/damage improve a little.
Unless you roll amazingly well, the majority of stat bumps are going to your classes primary stats. A wizard is going to increase their intelligence most of the time until they hit 20. They might bump Con or Dex if they feel they really need a boost to survival, but again, there's not an amazing depth of choice that really molds a character or represents how they change over time.
In the post I was initially responding to, you said
but I get to make a choice at 3rd level. That's pretty much it.
Attributes are a choice you get to make after that point. Now you might not see it as a real choice. You might see raising your primary stats as being so important you can't not do it, but I don't know if the game supports that idea.
The combination of combat/exploration/social model of 5th and bound bonuses, means that hyper specialization less desirable than say in 3.5.
If you hyper specialize as a fighter to be good in combat, you may well leave yourself unable to contribute meaningfully to the other two thirds of the game. Not to mention leaving yourself vulnerable t attacks against your attribute saving throws.
Now take into account the fact that a 12 basic orcs are still conceivably a threat to a 4 person 10th level party, and an a 1st fighter 13s in his primary and using a weapon he is proficient with, hits a CR 17 adult red dragon 25% of the time. In short, you don't need to hyper specialize to be good in 5th, you have a lot of wriggle room in 5th editions to improve other aspects of your character, and good reasons to not hyper-specialize, because you know, not failing cha, int, and wis saves as regularly may be more important for your character than making your str, dex and con saves a little more often.
So while it might not be a choice YOU would make, it is still a choice. It could be driven by the greater inherent viability of generalism is 5th, or by a desire to place an aspect of character concept over mechanical optimisation, but it is a choice.
Also a character learning more about the world, or becoming more perceptive are changes to the character.
As far as I'm aware, this has nothing to do with advancement. The choice is made at creation and is set in stone at that point. There are no choices of advancement or character development.
I actually think this is a missed opportunity. I like inspiration and tying it into options from the background, but pushing it further and continue to influence future choices would have been cool. Not just "what happened in the past influences the future" but actual new choices involving the background. Like if I choose criminal, maybe later one I could choose "reformed" or "crime lord". Knowing that I have this choice coming up at a future date would force choices in the roleplaying that feed back into making this choice later on.
While the thrust of your comments had clearly been that there were not many choices after character creation, you also voiced a concern that all barbarians would look the same mechanically.
I get to play the character how I want, but mechanically, if I made 3 barbarians, they're all going to be very similar to each other IMO.
Well, while there is some truth to that, your choice in backgrounds go a fairly long way to making characters different an unique, in a manner that interacts mechanics.
Now it is true that by default there is no way in which elements of background change(that i am aware off), it is a pretty reasonable application of common sense and rule zero that elements of a characters background such as ideals, flaws and bonds change over the course of a campaign. Not all character development is numbers getting bigger after all.
First off, you have to give up your ability score advancement. You can still get a 1 point boost in some cases, but this is a lot to give up. Usually the feats broaden options, but are relatively low in actual power, they're closer to a very mild form of multi-classing really. I looked them over and none of them really seemed that interesting. The ones that at first blush seemed like they might often gave me several things I already had access to. If I'm a warrior type, the warrior...
your entitled to you opinion on this but there are a lot of feats I would happily take rather than a +2 an attribute score.
Alert for instance, +5 initiative, never be surprised while conscious, denying ambushers advantage against you.
Or Inspiring Leader, with its awesome temp hit point buff.
Sentinel with its movement shut down and retributive attacks
Shield Master is basically a version of evasion, with added bonus to dex saves and a bit of battlefield control.
Great Weapon master Power attack AND regular bonus attack generation.
And that is before going into the really interesting feats like Observant that makes you a powerhouse in the social or exploration parts of the game. Seriously, in an investigative social section lip reading, attribute boost AND +5 to passive perception and investigation, that is absolutely amazing.
I am pretty happy to say that, as I play humans as a rule, most character I play will have two feats.