[X] - My reliance on my bloodline
uju does have a good point about this, and a lack of any defensive jutsu would tie back to the fact that Hisana has been relying about the Sharingan to learn ninjutsu.
This.
Hashirama beat Madara's EMS 1 on 1 while Madara had the Kyuubi. Sasuke didn't out-Sharingan Itachi, or come close to killing him via Sharingan.
Minato kicked the stuffing out of Tobi during the Kyuubi attack.
Danzo beat Shisui and plucked an eye out despite Shisui being a Mangekyo Sharingan user.
Tobi had to sacrifice an eye against Konan.
Sage Mode Kabuto was 2v1-ing two Mangekyo Sharingan users at the same time.
Madara spent most of his fading years attempting to evolve the Sharingan to Rinnegan.
Tobi collected most of the bijuu AND a pair of Rinnegan eyes AND tens of thousands of Zetsus before he felt comfortable going to war.
The extra powerups that we need to go to toe with the major threats in this universe are Fuinjutsu and Sage Mode.
Neither are Sharingan techniques, nor will they be helped by better Sharingan.
Sasuke and Naruto both get those transmigrant bonuses from Indra and Ashura; we don't.
And if we class into Mangekyo Sharingan, we begin to lose our sight.
Unlike Tobi, we don't have an entire bank of 100 backup eyes to choose from.