Yeah, I understand what you're saying. I guess what I'm tryin to say is, taking your example of a Dwarf Warlock, we know that Wyll is going to be a Human Warlock origin character. So, anything the Warlock portion of your custom character experiences, Wyll will experience by nature of also being a Warlock. That is, unless, of course, Larian is attempting to make unique story elements for every single race/class combo rather than separate unique things for each race and each class. Now let's say by actual launch that there's also an origin character who is a Dwarf. Now, as that origin character, you will experience the world interacting to you because you're a Dwarf. On top of these experiences, since you're an origin character with a handcrafted background and goals, you'll also be experiencing unique, handcrafted story content for that.
So, the question becomes, why do I play a Dwarf Warlock custom character when I could instead play two playthroughs with Wyll and this other origin character that have more unique stories? This is what I was attempting to say about the need for custom characters to have something unique about them. Similar to what this guy said:
Ideally, we would be able to chose from different personal histories, stroke of faiths, motivations and have NPCs react to that, rather than just to race and class.
Personal histories and/or motivations to choose from that are different than the origin characters would make them on equal footing.