Why is the XP awarded from an encounter the sum of monster XP values and not Adjusted XP? [closed]

Question

The Dungeon Master's Guide presents guidelines for gauging encounter difficulty based on the Adjusted XP of monsters faced. The Adjusted XP is the sum of the monsters' experience values, modified by a factor based on the total number of monsters in the encounter. Eg. an encounter against 3-6 opponents uses a multiplier of 2, meaning each monster's XP value is doubled when considering the difficulty of the encounter.

However, the XP awarded to the players is still the unmodified sum of monster XP values. It seems odd to me that while a larger encounter is more difficult in terms of Adjusted XP than two smaller encounters of an equal total size, the XP actually awarded remains the same.

Why is the Adjusted XP not awarded to players at the end of an encounter? Answers must be based on citations from the designers of DnD 5e.

Answer 1

It's only for comparing encounter difficulty

Mike Mearls, co-creator of 5th edition D&D, has an answer to this question shown in this link, coming from a Q&A in Twitter.

Someone asked him: "Why actual xp is given instead of adjusted xp? What was the design purpose of this?"

Mike Mearls:

it's kind of hacky - adjusted XP is there only for comparing difficulty. it's not "real" XP.

A second question: "If adjusted xp says something is more difficult, shouldn't players get more xp then?"

Mike Mearls:

not necessarily - the system is trying to capture the inherent difficulty in fighting more than 1 foe

Another question in the same site that is somehow related to this question, considering the game design focus, asks: "Thinking of houseruling that adjusted encounter XP = actual XP. Any reason why this isn't RAW? Any pitfalls to be aware of? Thx!"

Mike Mearls:

it makes hordes of weaker creatures a more appealing fight, if players metagame that. not game breaking

So there you have it in the words of a designer.