@lispi314 depending on who you ask, it was to coax people in to publishing. prior to patents you had a lot of trade secrets where people would hide everything. mathematicians for example kept a reserve stock of proofs to win competitions (they considered some of the theorems and proofs as personal trade secrets.)

this gambit still exists. if you patent ex. a silicon chip process you have to tell everyone how you did it. then there's just an international knife agreement that nobody is allowed to cheat and use it until the timer is up. if you tell nobody, then its a trade secret which is only protected from corporate espionage but if someone else independently discovers it (or just does a good job at stealing it) you have no recourse.

from an idealism perspective its supposed to let inventors talk about things with investors without investors being able to dupe it and cut the inventor out (this does not work at all in practice)

from a machiavelian perspective it migrates finance from textiles and crop monopolies to include other technologies. a study done on the crystal palace exposition showed no-patent nations tended to fund scientific instruments where patent countries had a much more active gadget economy (most of the gadgets being mass market garbage, but sturgeons revelation--90% of any given field is crap anyway)

from a practical perspective getting rid of it entirely puts you back at that trade secret corporate espionage dystopia again, but the duration is too long considering technology is increasing in pace. (copyrights/patents being 20 years was from a time that progress was quite slow.)