also unlike D&D your beliefs and ideals can change over time
this is probably what the problem with the alignment system boils down to for me - what someone's "alignment" is is incredibly fluid in both the short term and the long term (I don't believe I've EVER played a character for longer than 2 months who didn't have some sort of character arc that made their alignment at least trend in a direction if not outright change it), and not only that but what someone's alignment is is also completely subjective to the opinions of the people and society around them - or the opinions of the gods, I suppose. But then at the same time, D&D makes it absolutely, 100% clear that both good/evil and lawful/chaotic are actual inherent, physical qualities that a person has, something that can actually be scientifically measured, which is really strange
and then on top of this the alignment system just isn't very deep and doesn't describe people very well, it's just kind of... weak. good vs evil is a very boring way to define a person's character