I don't know about you, but it took me a long time to get here. I actually used to think of D&D (back in the '80s) as something like a setting-agnostic system. It's only after digging into those early books with fresh eyes after many years that I came to realize that the game Arneson and Gygax created is set in a world where all their influences from swords and sorcery and medieval high fantasy are in play. So Alignment isn't a way of understanding characters from fiction that was put in to help players role-play. It's part of the setting of D&D which is a place where Moorcockian Law and Chaos are really at odds with one another. That's why I use alignment in my D&D games, because when I play D&D, I want to play that game. I want to play the most D&D version of D&D I can play.
I think that's totally fair. But I also think it's fair to acknowledge that the game has evolved in all kinds of ways, that this isn't what suits everyone's tastes, and that there's a lot of opportunity to bring it to life in a totally different way for different settings and/or tables.
I'm not saying you're doing this, but I think anyone who feels the need to try to push how they view alignment as something that is objectively correct and that others are wrong for disagreeing with is behaving with extraordinary arrogance, and there are definitely people doing it in this thread.