It has always been the custom to hold a funeral with the body present. This derives from Christian belief that a) the soul, which is immortal, is an integral part of the body and b) the dead are raised to everlasting life in their earthly bodies. It’s therefore more than just logical to have the body at the funeral, it’s absolutely vital.
Do you believe that, or do you believe that the soul or spirit separates from the body at death? Many people look at a dead person and feel that whatever it was that made them them has gone — which is why people say that a dead body is “only a shell”.
If you believe that the spirit or soul survives the death of the body, and that’s what you want to focus on, the spirit or the soul, you may reckon the dead body to be an irrelevance and a distraction.
When John Lennon was killed, Yoko Ono wanted no focus on his bullet-ridden corpse. She had it cremated unceremoniously, unwitnessed. She held a memorial ceremony instead, to take place everywhere and anywhere. “Pray for his soul from wherever you are,” she said. And people did. Presumably this is what John wanted, too.
If you feel like Yoko, you’ll not want the body at the funeral. If you are an atheist, you may feel that the body is just so much old clothes; there’s no need for it to come.