Lee isn't a slouch when it comes to stamina, either. During his fight with Gaara, he was capable of moving around and dodging Gaara's attacks even after having used the First Gate, which significantly drains the body and left him much weaker. He was capable of enduring several of Gaara's sand attacks as well, which were stronger than he was, and was still capable of fighting and dodging rather efficiently. He still had enough energy to continue fighting and opening the other Gates. Even after having had his arm and leg crushed by Gaara, his muscles torn, he was still capable of standing up and preparing to fight on sheer willpower. And how about Lee's exercises where he does several thousand pushups, kicks, or walks around the village on his hands for several hours on-end, enduring the pain of pushing his muscles to the limit? Though Deku did do similarly harsh training, I don't think Deku ever did as many continuous repetitions as Lee did without resting.
Deku would have to land ALOT of hits to wear Lee down with attacks twice as weaker as him, while it would take much less fewer attacks for Lee to bring down Deku. And if the battle goes on for long enough, I think Lee would eventually be able to figure out Deku's movements too, since he's a taijutsu specialist with keen observation skills. I mean, I think it'd be hard for Lee, and it would take a while, but I don't see Deku expertly dodging every one of Lee's movements with ease even with his analytical prediction long enough to put Lee down.
