Most Uchiha are average at best, but the Manga had a lot of exceptional Uchiha, others whose chakra reserves had a cataclysmic enhancement. Your prime example is Obito Uchiha who got Hashirama dna.
Then we've got Madara, an exception among all Uchiha, who inherently had monstrous amounts of chakra, albeit infinitesimal in comparison to Hashirama himself. Then Sasuke, who by being an Indra incarnate, also had extraordinarily large chakra reserves. Evidenced by his ability to make at least 8 shadow clones, while Boruto, an offspring of Naruto, can only make 4 - 5, and will at best be able to make 6 - 7. Hence, Sasuke is not only a special case by Uchiha standards, but also as a shinobi at large. His chakra reserves are up there, but either way, his doujutsu powers don't really need anymore than average, as proven by Itachi being able to use his MS techniques for innumerable times, yet had the most meager chakra reserves, even smaller than Kakashi's.
In short, not all Uchiha will be like Madara or Sasuke or Obito. These were special cases. Madara and Sasuke were peculiarities due to their ties with Indra, and Obito had Hashirama supplementing his chakra reserves.