Why are vegetarian pepperoni slices so hard to find?

I just want to buy vegetarian pepperoni slices. We make homemade pizza kind of a lot. Against my wishes, my kids have been introduced to pepperoni which we've talked to them about why it's not good to eat animals, but I let my 4 year old make choices for herself, the 2 year old not so much yet. Either way, both of kids love pepperoni, so I'd like to get some. Anyway, I live very close to Detroit, as well as Ann Arbor with a lot of vegetarian restaurants and whatnot. I know from the internet that the are several types of veg pepperoni I could buy, but none available near me. I know I could buy a frozen pizza with veg pepperoni, but they aren't very good. Guess I'll have to buy my kids the new Little Caesar's plant based pepperoni. If that's not available near Detroit I'll scream.