my father is religious, I’m not and I don’t care what happens to my body after I die. Burn me, use me to feed stray cats.
To me, wasting money to buy a plot of land so I may be buried with them when I die is a stupid idea.
It is, however, his money. Who am I to disagree with him?
I think if it was me I wouldn’t worry about it. As you say, it’s his money and you’ll presumably outlive him, so then your options are: a) just leave it and then your eventual funeral stuff is mostly sorted, saving your loved ones a bunch of money and stress one day or b) you can just disregard it and do whatever you want.