The EMS has been proven to massively decrease side effects. EMS Sasuke was using the last stage of Susanoo casually without strain. And Madara is the reincarnation of Indra (so is Sasuke) but at his peak, at his prime.
That is like comparing G2 with G4...
I mean after the timeskip Luffy could easily use G2, but had problems with G4 right?
Perfect Susanoo is different, it is above the semi versions.
And Madara only had the mountain lvl with his perfect susanoo, his semi versions are far weaker and not durable as his perfect susanoo....
The whole point is aboutt perfect susanoo...
Because his DF is specifically designed for that. Creating vibrations over a large area. Causing earthquakes 500km away isn't a combat feat. Also, DC in form of a sword slash is more impressive, as it only cuts the affected area. And one one-handed swipe with the sword cleans the entire landscape and cuts through a mountain range with dozens of mountains. And Susanoo has basically 4 arms to hit a target with 4 swords at once.
You wanna tell me that Kaido not pose the similar power?
Kaido pose that lvl already in hybrid, Madara need his strongest form to do similar feat...