I'm willing to listen just prove it if u can I'll admit being wrong I'm not biased I'm goin by what I seen in the manga
Okay, so if you have that resolve, then I'll probably give it a shot...
To compare Sage Mode to the Rinnegan, let me first give you a little insight of the Naruto vs Pain fight:
1. Nagato was an Uzumaki i.e. he wasn't the original owner of the Rinnegan. This means that he couldn't use the Rinnegan to its maximum capacity since only the original owner can utilize the full potential of the Rinnegan.
2. In addition, Nagato was using the Six Paths of Pain. This means that his chakra was being distributed evenly among every Path, so every Path received 1/6 of Nagato's chakra, which means that Nagato could only use 1/6 of the total power of his jutsus from each Path using the Six Paths of Pain.
3. On top of that, Nagato was channeling his chakra to the Six Paths of Pain, so the strength and speed of his jutsus was considerably decreased.
4. On top of already not being able to use Rinnegan's full potential, and then using only 1/6 of total power which is further weakened by decreased strength and speed of jutsus, Nagato had already used so much chakra in his battle against Konoha. He fought so many shinobis including Kakashi, not to mention the almighty Shinra Tensei which destroyed the entire village. All this activity prior to his fight with Naruto consumed a huge amount of chakra, so he didn't start his fight with full chakra level or stamina.
5. On top of already not being able to use Rinnegan's full potential, and then using only 1/6 of total power which is further weakened by decreased strength and speed of jutsus, and having used so much chakra before and slight exhaustion, and even on top of losing all the other Paths including the regeneration Path as the fight continued, he easily fought Naruto and effortlessly pinned him down using only the Deva Path.
6. Even after all the aforementioned reasons, and fighting with only the Deva Path, he could have easily killed SM Naruto, only if he wanted to. Since Naruto was a jinchuuriki, he couldn't kill Naruto. So, Naruto had a tremendous advantage due to this restriction.
Therefore, the conclusion until now:
Deva Path only (without Rinnegan's full potential, with an immensely depleted chakra reserves and considerably exhausted, and the strength and speed of his jutsus decreased, and even having no intention of killing Naruto) > SM Naruto
7. So now we have a severely weakened, exhausted and low on chakra reserves Pain (Deva Path only, mind you) who can't use the maximum strength and speed of his jutsus, and can't even use Rinnegan's full potential, and has no intention of killing Naruto, even after that he was able to counter Naruto's six tailed form, full of rage, and fought on par with him, and eventually even dominated Naruto's six tailed form using Chibaku Tensei.
Conclusion till now:
Deva Path ONLY (without Rinnegan's full potential, weakened, exhausted and low on chakra, decreased strength and speed of jutsus, plus no intention of killing Naruto) > SM Naruto + Six Tailed form (enraged)
8. Even after ALL THAT, Naruto was completely owned by Pain. So he had to push further and unleash the eight tailed form, only then he was able to fight back Pain with the upper hand.
Let's summarize again now:
SM Naruto + EIGHT Tailed form (enraged) > Deva Path ONLY (can't use the Rinnegan's full potential, weakened, exhausted and considerably low on chakra, decreased strength and speed of jutsus, plus no intention of killing Naruto)
OK, so that's what it takes for SM Naruto including immense assistance from Kurama to overpower Pain (Deva Path only) who had so many disadvantages on his side and couldn't even utilize Rinnegan's full potential. Impressive!
9. Even after all that, Naruto completely ran out of Sage Mode while Nagato still had enough chakra to revive so many of Konoha's shinobis. Even then if Nagato wished to destroy Naruto, he could have easily done that, unless Kurama intervened again to save Naruto.
That's a summary of their fight. BTW, we've already seen how well Nagato (who couldn't even utilize Rinnegan's full potential) could handle Naruto, Bee and Itachi combined and completely owned them, during the war. If it weren't for Itachi's timely Totsuka Blade sealing and timely saving Naruto and Bee on time, they would've been in serious trouble. That my friend, is a glimpse at the power of the Rinnegan. Sage Mode is almost nothing compared to the Rinnegan.