The two main problems are how to manufacture them at scale, and how durable they are. A thin outer layer on your clothing tends to get fairly rough treatment.

The two main problems are how to manufacture them at scale, and how durable they are. A thin outer layer on your clothing tends to get fairly rough treatment. Think about sitting down, then scooting your butt back. How much force was that? Amd if this is anywhere other than the outer layer, it won't work as well.