Literally zero.

Everybody keeps every dollar they own physically on them at all times.

These dollars do not have to be printed, the cotton does not have to be woven, the plastic does not have to be stamped, the dyes do not have to be mixed, nobody has to account them, nobody has to account for their storage, nobody is maintaining the number and circulating supply of them, nobody is regulating the distribution and influx through centralized institutions.

Sounds like a cakewalk.