Funny that you call a 9 dan player’s understanding “a beginner’s interpretation”
That being said, The manner by which the AI prefers the 3-3 has been thought very widely, and “simplification” has not been on the high list of reasons it does so, otherwise it would choose variations with far less aji.
Your op does mention that influence has changed radically, and I personally believe it’s a shift towards analyzing in more detail about how influence has to be a fighting power that can be used in certain concrete ways. No more is a wall simply influence for being there, particularly if there is a weakness to threaten such as in the AI exploitation of the older variations.
Because influence is, chiefly, for fighting. And fighting with a weakness necessarily reduces the power of said influence
And AI has shown that older enclose-and-extend methods are easy to make inefficient, as it is not as powerful for fighting in extended positions, and maybe overconcentrated in more secure positions.
Simplicity doesn’t factor here at all, in fact the AI frequently makes complications in places that older theory had found unsettling to professionals. Not to mention simplicity does not claim points, at best it will secure a lead if you already have one. So to claim it’s the basis of some of the first things AI does in each game is patently absurd.