Aren't origin characters just a video game interpretation of pregenerated characters that exist in DnD? Some people are just not very creative when it comes to characters and could use a solid story already prepared for them. As for the other concerns - I enjoy BG3 and I enjoy DnD. They are not the same in my head and it brings me much joy to be spared of this inner struggle because of shoves and stealthes etc.
Not that I'm aware of. The origin characters are completely Larians invention. I think there are one shot adventures in DnD with pregen characters, but DnD is in my observation the game, where people are most inclined to make their own characters.
"We are all stories in the end. Just make it a good one."