Because all those people have a sharingan you dumbass. Minato doesn't have one. He can't automatically cancel all genjutsu that's not tsukuyomi, or initiate a genjutsu face off the second itachi does one.
So minato's going to start the battle with sage mode active and his eyes closed...? I mean come on... You guys can't even argue how minato gets past the first genjutsu. Literally every single person who's face itachi, down to kakashi's shadow clone, has been caught in a genjutsu from the onset but minato won't be? :vincent:
and, btw, just to list the 'everyone' i mentioned;
-Orochimaru was caught from the start
-Anko was caught from the start(her genjutsu reversed)
-naruto was caught from the start twice or thrice.
- sasuke was caught from the start (as a kid and in his 1v1 with itachi)
- deidara was caught from the start
the only person who wasn't caught from the very start was kakashi because of the sharingan. IE itachi opted for tsukuyomi because his sharingan would auto-see through other genjutsu making it impossible to incapacitate him with basic genjutsu. In other words no sharingan = no good.
*sasuke broke tsukuyomi. Something minato can't even do.
It takes itachi's sharingan being on for you to be caught. Something he starts every fight with. There is no conceivable scenario where what you're saying is honestly possible. This fight has to start with them facing each other unless one ambushed the other. In which case, the minato the other turns to face the ambusher, minato's caught in a genjutsu.
This of course based on your previous claims