Except no one is saying that you are having badwrongfun or that you are less advanced. The original post was essentially a reflection on scenario design and how to create factions with varying agendas. Other posters have commented on how your setting might be different if you use a cosmological/objective notion of Evil and Good vs a subjective understanding of good and evil as in-world characterizations.I don't think D&D needs dungeons or dragons. I rarely use either. It also doesn't really need attributes, saving throws, multiple races, monsters.
But I like having the PCs being the good guys fighting evil. Not every opponent is evil, but having a BBEG is part of the fun for me.
On the other hand, this whole thread seems to be just another "alignment is bad". Playing D&D as a fun high fantasy campaign is somehow bad-wrong-fun, or at least bad-wrong-fun adjacent. That for more "advanced" gamers, all morality is a gray abyss.
It's difficult to have a discussion when venturing any sort of opinion counts implies "badwrongfun." If you like Good vs Evil, you do you! I would even say Evil is necessary if you want to lean into high fantasy or perhaps in a planar great wheel campaign.