Itachi can put people under genjutsu from clones, crows, finger, eyes, even without using the enemys' 5 senses(Izanami, in certain cases).
He has shown much more feats in incorporating genjutsu in his battles in various ways, others have not. Just simple user->enemy eye contact genjutsu.
Itachi is more skilled in trapping enemies in genjutsu. Tsukuyomi is a powerful genjutsu, damaging and crippling enemies in a battle, I can't believe how people portray it as something weak just because of godly IT and koto, which hasnt shown any destructive/offensive feats rather than just manipulating someone's brain without them knowing.