The conventional natural monopoly argument assumes that all firms
must pay the fixed cost.
This is physically not true for information!
At least with digital information, entrants can make a perfect
copy of the incumbent's information -> entrants produce at zero
cost.
Use licensing to enable reproduction, award revenues to original
developer, and avoid new fixed costs.
A license is a contract, so the user must agree. The user will
not want to agree to pay if he has the right to use the idea
without paying. Thus the government issues copyrights and patents
(intellectual property).
Intellectual property by definition creates a monopoly. The
economic loss due to monopoly is intended to be balanced by
avoiding redundant investment.