It took Madara decades to achieve this power and he was lucky that it even happened. Sasuke without senju DNA or any kind of hack besides itachi's eyes (did not contribute to awakening the rinnegan) obtained a rinnegan more powerful than the two rinnegan Madara spent decades trying to obtain.
1. Madara obtained his power alone and wasn't given anything but Izuna's eyes.
2. Sasuke was given Hashirama's DNA to help revive him. Note it wouldn't give him the Rinnegan since Naruto DNA would be needed for that as he has Ashura's chakra in him and not Hashirama's old DNA.
3. Sasuke used hack when he used Oro's drug in part 1 to increase his base stats and gain CM lvl 2, used drugs or forbidden jutsus to increase his growth speed. Hacked that Itachi have to plan around their whole fight in a way that not only takes Oro out of Sasuke but have himself die by Sasuke hand and give him MS while leaving him EMS and the explanation of both MS and EMS prior.
4. The Sage didn't even have any good reason to give Sasuke some of his power except that he felt bad for ignoring Indra
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