"The last" did not say this. It was a character that did, who was very intimately involved with the matter. Characters can be biased, characters can make ridiculous assumptions about the other's feelings. The opinions of a character on the other character are not taken as hard canon. The point that Naruto didnt love her out of a rivalry still stands. We, as readers, who have seen all the interactions of the character, can make much more objective judgement than an in-story character that has biases and a limited knowledge (comparitively).
You know what a Retcon is right?
Naruto loved Sakura in the manga, it's quite clear he did. The Last retconned this and made it all a rivalry
RETCON =
(more common usage) Adding or altering information regarding the back story of a fictional character or world, regardless of whether the change contradicts what was said before.
Sakura said that rivalry thing and Naruto accepted that, it is difficult to understand that? You can still like how Naruto's character was before all this ending made him look bad, that's what most of us do anyway