My 2024 DMG came today so I was able to look up this "rule" since I felt like it lacked context.
here is the text:
Setting clear expectations is essential when dealing with this kind of rules exploitation. Bear these principles in mind:
Rules Aren’t Physics. The rules of the game are meant to provide a fun game experience, not to describe the laws of physics in the worlds of D&D, let alone the real world. Don’t let players argue that a bucket brigade of ordinary people can accelerate a spear to light speed by all using the Ready action to pass the spear to the next person in line. The Ready action facilitates heroic action; it doesn’t define the physical limitations of what can happen in a 6-second combat round.
The Game Isn’t an Economy. The rules of the game aren’t intended to model a realistic economy, and players who look for loopholes that let them generate infinite wealth using combinations of spells are exploiting the rules.
Combat Is for Enemies. Some rules apply only during combat or while a character is acting in Initiative order. Don’t let players attack each other or helpless creatures to activate those rules.
Rules Rely on Good-Faith Interpretation. The rules assume that everyone reading and interpreting the rules has the interests of the group’s fun at heart and is reading the rules in that light.
Outlining these principles can help hold players’ exploits at bay. If a player persistently tries to twist the rules of the game, have a conversation with that player outside the game and ask them to stop.
First and foremost, this was presented as a way to combat players exploiting the rules in an unfun and unfair manner. To apply them as primary, broadly applicable principles for 5E 2024 in general is, I think, wrong. I also think that if we are going to talk or argue about these principals, we should have the full text.