Which classes of egyptians participated in death rituals?

The highest classes such as the Pharaoh himself and his loyal and royal friends. This was because they had enough money to build pyramids and organize burial rituals and thus brag of their wealth even in death.

Egyptians participated in death rituals in cases where they had enough power and prestige to be able to afford them. An example of these would be pharaohs or high priests. These were two classes of people which were able to afford death rituals, while other classes in Egypt couldn't.