In the past 10 years, 4 times an 8 or 9 beat a 1 seed (2 in 2004, 2011, 2013)
In the past 10 years, 10 times a 7 or 10 has beat a 2 seed.
In past 10 years, a 2 seed has lost in 1st round 3 times.... so two more times the 7/10 went on to Sweet 16. And last year a 15 seed went to sweet 16 for 1st time
So 4 times a 1 seed has failed to make Sweet 16 ...... and 13 times a 2 seed failed to reach the Sweet 16
It's still about having the right matchup, but the odds will say that being a 7 or 10 is better to reach the sweet 16.