I bought some groceries today. I spent some time walking through the produce section, looking at what fruits and vegetables might be available for a good price. Potatoes of various kinds were around $1 a pound. When I looked at a box of store-brand potato flakes, they were $1.55 a pound. Given that the flakes would, when reconstituted, make up easily 6 times their dried mass, that means that potatoes would need to get down to about 25 cents a pounds before they were competitive with the professionally made flakes, even discounting the time and effort spent making flakes, the energy required to boil/dry/pulverize them, and the water.
In short, it's better all-around to just buy dehydrated flakes. It takes less energy to ship them, and the packaging is even plastic-free. This is not the end of my time dehydrating foods. Some things are not available at all in a dehydrated form, and many others are available only with a lot of single-use plastic packaging. Some are more expensive when purchased in a dehydrated form than when bought on sale fresh and dehydrated at home. Of course, I cannot dehydrates some foods at home and maintain a reasonable quality; eggs, for example, or milk. This is just an overall reminder to me that no one approach is always the best.