The original intention of copyright was the same as that of patents: To encourage the creation of new works by making it possible to monetize them through licensing
Not that it really changes much of your larger point, but that’s not really true. The original intention of copyright comes from the Licensing of the Press Act 1662 and the Statute of Anne 1710 and neither of those was intended to encourage the creation of new works. On the contrary, they were intended to discourage the creation of new works. The problem at the time is that people were printing too many new works, many of which were considered a threat to the monarchy and/or the church. Copyright forced all printers to be registered with the Stationers’ Company initially (a crown-monitored guild) and later the crown itself, to aid in censorship and government control of the press.