Pizza adjacent:

Some clever fellow decided to shave a nickel by padding their shredded parmesan with sawdust and now the other brands of parmesan have "No cellulose!" on the label as if that is a selling point. Which it is, now, alas.

https://www.theguardian.com/lifeandstyle/2016/feb/17/parmesa...

there are different flours available which vary in suitability for different purposes and in cost. King Arthur Flour has a computer controlled mill and they offer a service to bread makers to let them specify their own "recipe" for the flour they wish to order.

https://www.cooksinfo.com/flour-grades

excerpt:

"French bakers will use straight flour in their bread making; North Americans and British generally don’t.

"Straight flour is separated by sifting in other grades. The straight flour is passed along a roller over different sieves. Different grades fall through the appropriate sieve along the roller. In the percentages given below, the lower the percentage of straight flour that falls through a particular grading sieve, the more desirable the flour."

>why would you bother with a substitute for a regular pizza?

Shelf life, reduced calories, ease of working with, etc, etc. Basically all those secondary goals you optimize for once it's a given that the pizza will pizza properly.