I flew United yesterday from IAH-DEN and every seat on the plane was occupied. Part of it seemed to be that about 20-30 standbys were cleared at the gate.
The flight mostly went well although upon landing I saw at least five people just in my immediate area pull their masks down, exposing their noses and mouths. It might be good for United to remind everyone to keep masks on through the deplaning process.
The DEN airport seemed fairly busy and I was surprised by how many people there were not wearing masks, including airport workers.