Well, ok do he did a lot of work and came to a conclusion, it's worth respecting the work sure but there are still massive differences in gsme to game play.It’s obvious he has put in the work. That right there is more than most people ever do. And his methodology seems fair and without crazy bias. Also, he is pretty highly regarded. Not by you, obviously, but by a lot of people in general.
To me and my play, Mage Armour vs Shield, if I ignore Magic Misdile defense, it comes down to math.
Made armor tends to make a difference of 1 hit in 7 attacks.
Shield tends to make a difference every time it is used.
So, I have to be attacked like 10-14 times before mage armor passes shield.
But, hey, wait, of those 10-14 attacks, how many hit anyway?
As an AC 15 mage armor wizard, against just ten attacks with maybe a +2 to hit, that's still four attacks that got thru. At first level, if we assume thsts two separate encounters, that is likely to drop me anyway. If we raise it to 14, now I am taking six successful attacks even after Mage Armor.
That is not a sustainable environment and tactical play style.
At the frequency of attacks needed to make mage armor msthematically superior to Shield just for stopping hits - the Mage is pretty much toast.
So thats why I dont like made armor over shield. I am losing anyway if I am getting the mileage out of it because for every hit it blocks I likely am taking three others over it.
I am much better off casting other spells like Fog Cloud or Silent Image or Magic Missile or Charm Person or Thunderwave etc etc etc thst csn seing a battle more significantly than a Mage Armor thst doednt save me anyway.
Heck, False Life is even likely a better choice.