What would be the value of physical Bitcoin for the users and how does make storage, its main use case for now, better and safer from theft?
It will I guess depending on the quality of the physical coin, if it is made of gold, of course, the price the same on gold, but if your physical coin made on copper then the price is cheap than the gold. A physical coin is almost nothing valuable except if many crypto enthusiasts treat this as a souvenir coin.
The most physical coin is not intended to make for storing your digital bitcoin that has a value, but I saw there is a physical coin that has an address inside and has a digital bitcoin, maybe that is a paper wallet that the seed is separate to the physical coin. Regarding the demand and supply, just ask above, that dude selling physical coins.