Important although semantic reminder that they’re “less lethal” not “non-lethal”.
The difference is that less lethal means they must be used as intended, otherwise they can result in injury or fatality. This is different than non-lethal weapons/ammunition.
Per the UN Peacekeeping Standards for Police (page 6):
Less than lethal ammunition (weapons), also known as riot control ammunition, is a general title for ammunition of various types which may be used in circumstances of civil disturbance to disperse riots or to incapacitate individual rioters, or in hostage rescue or other police operations. It is designed to minimise the risk of death or serious injuries when used as intended. It is important to stress this latter point, as any of these rounds can inflict severe injuries or result in a fatality if used improperly, which is why weapons and ammunition of this type are now known as “less-lethal” (L-L) rather than “non-lethal”
Great write-up! As you say, the whole misnomer is really the icing on the cake for how ridiculous the history of these are.