I find the circular arguing about what is or isn't DnD to be wasteful. Strip the purity arguments away and you find something more compelling - that there are very good reasons why very few developers in the gaming industry are pushing the system as hard as what Larian is trying to do. And it has nothing to do with Larian trying to push any boundaries in this department, as this isn't some budget thing.
The real thing people should be focusing on is that the Origin system simultaneously diminishes the importance of a custom character, AND robs the actual companions/origin characters of their agency. The latter is concerning in ways rarely ever brought up in these parts, indirectly stripping down their characterization due to the idea that they have to remain somewhat open-ended in order to become potential lead characters, instead of actually being allowed to become their own thing. All in the name of dubious 'replay value' that only really translates to maybe 10-20% of the content being changed in any meaningful way. All these development resources sunk into the system and sacrifices being made in other areas, for what in the end?
Someone brought up that the origin system may largely exist for multiplayer, but let's be realistic, the vast majority of DOS2 multiplayer sessions I had participated in had people rolling custom characters, and nobody really gave a shit about the story. The only sessions where origin characters were used were those that weren't composed of full 4 player groups.
And before people bring up WotR in an attempt to have some gotcha argument since that game does heavily emphasize replay value, there is one MAJOR fundamental difference between the mythic paths and origins. The mythic paths change the way you approach quests, had major story differences along with changing how many of the game's characters reacted to you, and factor heavily into your actual builds during gameplay. It's a lot more than having a few cutscenes and story snippets gated behind them, which is what all the Origin system really did in DOS2 and promises to do in BG3 thus far.