Carol Danvers is without a doubt a Cosmic hero who showed she was that and then some in Avengers: Endgame, but with few people to use that immense power on.
Perhaps she could tangle with Silver Surfer on his way to Earth and give audiences a god-like superhero showdown?
As it stands, there aren’t a lot of cosmic-level entities in the MCU.
Ronan The Accuser and Ego were considered Cosmic-level villains in the comics, though some would debate on whether their powers were nerfed a bit in the transition to the MCU.