Umineko is funny because when it is at its best it's a witch going "look, it's magic, this is magic, I am using magic to mAterialize shit in front of your fucking eyes" and on the other side is the dumbest boy alive going "nuh-uh, just because I am dumb as dirt it doesn't have to be magic".
And this is somehow entertaining. It's a dumbass going "I've watched too much Scooby Doo so I'll believe impossible contrivances are possible and I am just too dumb to know how before I'll accept the supernatural" and it's fun!
But then there's also the constant, endless, repetitive exposition.