If the pharmacist with his license on a piece of driftwood had satisfied customers that I’ve spoken with, lines at the counter, and lower prices than the other guys do, then I could get used to checking out the broken beer bottle while my Rx was getting filled.
Until beachcomber boy misses a drug interaction and you drop dead. Then you can be taken to the mortician. Since he would probably also be unlicensed in your world, you'll probably be embalmed with Gatorade.
The free market can solve almost all problems, but insuring that people in crucial professions where a single mistake can be a disaster are "ready to solo" is not one of them. Getting rid of licensing for "libertarian" reasons is just as silly as requiring ever profession to be licensed.