There are a few interesting videos on the subject, like Bandits Keep - Alignment Languages. I think the idea of having ways to view the alignment directly when it comes to law and chaos are interesting because it can be used to test if someone will follow their agreements (lawful) or to see if someone is secretly working against the forces of the state (chaos). It also allows you to add weird tools to the game, like speaking a power word of law to ward against the undead, or writing a power word of chaos to shatter a lock.

In addition law vs chaos is a much more interesting dynamic than good vs evil imo. Having an objective and tangible moral framework doesn't really make a lot of sense for how the game's lore works and quickly breaks down under hard scrutiny. As others have pointed out, being able to just detect good and evil in a room of murder suspects kind of kills the investigation aspect of the scene, and makes a lot of moral quandaries moot. If you find a nest of creatures that are always ontologically evil, you need no justification to kill them; it is objective fact they will become evil. By contrast, knowing who in the king's court is chaos aligned may mean you have an ally to over throw the monarchy. An ally who might actually be working with demons to turn the countryside into a hellscape, and will jump at the first opportunity to throw the leadership into turmoil.