Can anyone be better than even the lowest person of the sahaba?

The feeling I get from people is that no individual can ever reach the rewards of the sahaba in jannah, not even the single lowest sahabi. That didn't sit right with me. Intuitively, I thought as a generation, none will ever reach their ranks in jannah. But that individuals may rise in rank above the lowest of the sahaba perhaps?

Like what about martyrs of today and the future, won't they get higher rewards than the sahaba that didn't get martryed? What about the mahdi - he will lead the ummah during the greatest test to mankind, EVER, won't get a reward in jannah greater than the very lowest of the 100,000+ sahabi? What about the hadith concerning the greatest martyr in the eyes of Allah who will stand up to the dajjal, won't he get a reward in jannah greater than the very very very single lowest person of the 100,000+ sahabi???

Is there conclusive proof from Qur'an and/or hadith that no single human can ever surpass even a single one of their rewards in jannah?