You specifically mention the tradition of visiting the graves of deceased ancestors. All over the world where funeral rituals existed, such recurring visits probably took place, even to the point of a cult of the dead. Now, in this country, the understanding is shifting away from religious belief in the afterlife towards a biological-technical expectation: decay and transition into the cycle of nature. There is no need to complicate this with a coffin, nor is there any need to celebrate it as something special. We all die. I would like to be buried somewhere, anonymously, without any marking on the grave. No one will come to visit me, because the only important things are the memories associated with me and life in the present. Isn't there a saying somewhere: Let the dead rest in peace?! Take care of the living ;-))