He wanted the EMS to surpass the hyped EMS Madara.
Hype that Obito was purposefully using to his advantage against the world.
It's not that difficult to see the parallel there.
Itachi knew that "Madara" was weakened and hiding in Akatsuki's shadow, and called "Madara" a bitter loser. "Madara" also only apparently had one eye so that means only one MS jutsu.
The Kages were smart enough to call Obito out on it, saying that Madara's powerful enough to do anything he wants, so why was he using roundabout tactics. Obito then said that he (as Madara) isn't as strong as he used to be.
Surely the Gokage aren't smarter than Itachi,. right?
well we've seen Yatas mirror used in battle, it is yet to be broken. extracting and using the Gedo in battle is different, the Gedo is doesn't even walk which is useless because he is a sitting duck
Yata's feats so far are is blocking some kunais and Sasuke's sword, hardly enough to warrant the no-limit fallacies that fans often give it based off of
hype.
Gedo Mazo does walk, what are you talking about? It also handed giant Butterfly Chouji his ass and took down an army. Point is, Obito could use it.
Indeed, if he wasn't afraid of him, he would have went ahead with his plans anyways not caring for what Itachi wished. Also, remember that while Itachi may have been worried about "Madara" and his EMS, Obito himself knew he was not actually Madara and was not capable of defeating Itachi
Obito WAS carrying out his plans regardless of what Itachi wanted.
He still hasn't attacked Konoha even after Itachi's death.
He didn't care about Konoha, he was mocking Itachi for making a sham deal.
Obito was confident about fighting Edo Itachi.
And the end of the day, Itachi was one of Obito's greatest pawns.