It also depends upon the foot "deformity" ... i.e. rearfoot varus versus forefoot valgus, is the hallux plantarflexed, if so is it rigid, etc.
Some foot deformities do not do well barefoot. An orthotic helps the person "ground" much better ...
But some people do much better barefoot ...
I agree that in general people's intrinsic foot muscles have gotten weak ... especially women who wear high heeled shoes a majority of the time ... and the exercises to correct it are difficult to do and to explain and take a lot of practice. I'm not convinced that just walking barefoot or working out barefoot would fix it.
That said, IMO, there is nothing better for your feet muscles than barefoot walking in sand ...
