I’ve seen a lot of people using Tobi’s eyes to make an argument about this, but I’m going to take a different approach.
At the start of the series Kakashi was 26. This means that when Naruto was born he was 14. Kakashi and Obito were the same age, so if Obito some how lived he would be 14 too. If he died and someone took over his body somehow, his body would be even younger than that.
This is Tobi and Minato together when he tried to kidnap baby Naruto.
Tobi and Minato are about the same height. That is not the body of a fourteen year old boy, especially considering that Obito wasn’t very tall to begin with. When he died, one year before this, he was 154 cm tall while Minato was 179 cm. A thirteen year old who has just suffered a serious injury does not grow 25 cm in a year. Therefore, Obito is not Tobi.
jesus thank you