I saw this Ted talk by some scientist who researched all the various types of composting and according to their data at least, using just leaves turned out to be the most rapid, efficient and effective medium for composting detritus into fertile soil. Egg shells and all the other stuff we use will eventually break down, but it doesn't break down fast enough to disperse its nutrients among the soil apparently, so you have bits and pieces of extremely slow to break down matter, whereas with leaves, everything breaks down rapidly and uniformly. I tried it myself and I've always found eggshells and orange peels in my compost weeks later, and even once got a fungal infection in the soil that killed a houseplant, but when I used leaves, especially dry leaves that I crinkled up with my hands first and then mixed into the dirt I was gardening with, I instantly had premium soil.
I don't want to discourage the way you or anybody does composting, I just found this talk very interesting and after trying it myself I did like how homogeneous and healthy the soil was after I went to just leaves as compost.
Let me find the talk in case you're interested.
It's been a few years, but I believe this was the guy: https://youtu.be/n9OhxKlrWwc