imagineGod
Legend
You make good points. The way earlier Edition spells and magic items worked based on alignment no longer work that way in 5th Edition.I think that what alignment was used for has been superceded by other systems that do it better (with one exception).
In my understanding, alignment is used for Character Behavior, Spell Effects, and Enemy Behavior.
Character Behavior is now mostly motivated by Background, Ideal, Bond, and Flaw, which often uses the language of alignment! There are Ideals which explicitly use "Chaos" or "Evil" in their description.
Spell Effects now use creature type instead of alignment, such as in the spell Protection from Good and Evil.
The one gap I see is Enemy Behavior. That's why I think it should be replaced with some codified traits that a DM could use to easily make decisions about how their enemies act.
An improved shorthand system to Alignment would be welcome by most DMs running monsters on the fly. Reality check. Wizards of the Coast has no alternative yet, if they did, we would have seen it in defined properly Tasha's like we saw with racial Attributes, and then exemplified in the new Ravenloft stat blocks.
Sadly, WoTC was blindsided and just threw the toys out for everybody as a knee-jerk reaction.
And everything became smelly when stat blocks using full words for alignment instead of two letter shorthand.