Chelsea is a weird team. They just knocked PSG in a flawless victory in UEFA Club World Cup in USA and prevented them from having all cups season then they got an epic goalless draw against Crystal Palace in the opening round of this season.
Manchester United in the other hand could do better in yesterday's match, the defeat was preventable and at least a draw would boost their weak psychology in my opinion.
I agree with everything that you said. Much was expected from Chelsea yesterday, but they gave little. However, Crystal Palace is a pain on the ass for big clubs in EPL. They have defeated Manchester City and Liverpool in the finals. This shows that Chelsea tried their best to draw the match. I just observed that any team that defeat Liverpool, Arsenal or Manchester City finds it difficult to defeat Chelsea.