[renowner]

Cloak of Many Colors is a very good item, but it doesn't invalidate all other item choices by existing. Its useless completely against people who don't use those elements, and also doesn't have any fp boosts, stat boosts, or special effects. Unarmored torsos have a wide variety of useful armor they can utilize and none completely invalidate the others. . . For the most part. Embroidered gis are just better. And there's some unarmored equipment pieces like animal pelt that are just useless.

This armor invalidates pretty much all other heavy armor ,and is still extremely good even against people who don't trigger its main effect. And has very low weight.
Heavy armor already has a lot less worthwhile choices than unarmored to begin with.