Less likely for Cinderella teams to win
No, Cinderella runs are unaffected, mickey mouse runs are just impossible. For example Zeta at Reykjavic and EG at Tokyo were both cinderella runs (Double Elim) .
In single Elim, we had Karmine Corp (like the worst t1 team ever, by far) look promising vs LOUD and Furia be competitive vs Fnatic. These are mickey-mouse performances that double elim (and a qualifier) would have prevented from affecting the result, should those games have gone the other way.
Upper bracket games feel less suspenseful (Because even if they lose they’re not out)
If you don't understand that literally every match is extremely important, then I don't know what to tell you.
For many matches in the lower bracket, one team has more time to prepare than the other
Extremely marginal issue, far outweighed by the benefits of double elim.
So many games takes away the gravity of each one
Erm... No it doesnt??? Literally just more to watch?? It's not like the stakes/importance of one match is decreased by another equally important match being scheduled 30 mins later.