What I have determined is that for many things in life you don't do them because they make sense or that you care about them, but you do it because it is important to someone else and that someone else is important to you.
Kindergarten graduations are like this. My kids put on a play, they danced and they were very proud. It was stupid, but I went and cheered because it mattered to them.
I will go to my kids High School graduation, but I won't go to anyone else's. Why? Because graduating from High School is expected in our family and is not a celebratory event...but it is my kid. But my kid and almost every other kid doesn't want to be there. Parties, gifts, sure...but the event itself is almost as bad for them as for everyone else.
Other peoples kids (even relatives) can get a gift or a check, and if there is a party to attend with family in the vicinity I would go if they invited me.
Otherwise...no.*
*Note: Unless my wife says otherwise and makes it more unbearable to deal with her than to suffer through whatever shitty event du jour I am dealing with.