My main gripe is that humans don't have much meat on them. It works in a pinch, but the effort needed to eat so far outside of our normal pallette isn't worth it.
That said, I would be in favor of letting nature decompose our bodies more. I hate having to waste so much effort on disposing of bodies, especially once I die. I want my body to get torn apart by animals, not buried with holy rites. Mummification is the only burial practice that seems kinda cool. Cremation seems unnecessary, especially if I can get eaten by something instead. Just take what's useful, chop me up a bit, and throw me in the compost!
That can kinda be arranged, actually. Something that came up during one of Caitlin Doughty's videos is a nature preserve type place in Florida that they protect by burying people there to decompose naturally. I'm not going to look for more info about this on Christmas though, lol.