Interesting that many commenters use the 'make an idea public' argument for patents. However if reinvention and rediscovery of an idea doesn't happen that often

Interesting that many commenters use the 'make an idea public' argument for patents. However if reinvention and rediscovery of an idea doesn't happen that often then you why would you need patents anyway? Penn and Teller's Fool Us shows demonstrate that very few magic tricks are undiscoverable to other magicians. So just hire one to work it out. That increases the value of magicians and decreases the value of patent lawyers, patent reviewers, patent writers and the patent trade. Surely that is a good thing?