Even though it annoys me to say this but Naruto moving on but could've been integrated and it could've made some sense if it was done right. Have Naruto confess and then Sakura tells him sorry I just don't have those feelings for you. And then Naruto moves on. That's the problem all that love that Naruto had/has for Sakura was just forgotten and not mentioned again. Like it didn't even exist.
How could Naruto have moved on and still look heroic though? Kishi used the excuse that Sakura moving on would make her look like a terrible woman. However, the manga isn't called Sakura. Or Sasuke. Or Hinata. It's called Naruto. He didn't let go of his feelings towards Sasuke, no matter how edgy he got. He's not supposed to quit. Out of anyone in the manga, he's supposed to be the one portrayed as never giving up.
There is no believable way he could have stopped loving Sakura as the hero of the manga. It's shounen. It's not supposed to be this complicated >.<