The main problem with Oasis is they simply have not evolved at all. The songs they release today could so easily have been released in 1994.
Oasis as a group are far and away bigger than Blur ever were. However maybe in 30 years time when all involved are long retired, I suspect Blur will be seen as the more talented, and Oasis as a band too obsessed with The Beatles.
It's ironic that Noel Gallagher refuses to change his bands style in a sort of homage to The Beatles, yet does he not see what kind of transformation Lennon, McCartney and Harrison were capable of in going from Love Me Do to Strawberry Fields in the space of barely 5 years?