seems like not that long ago i would've thought that the idea of a PC without any disc drive was insane. i had to help a neighbor kid the other week when forced bitlocker bricked his gaming PC, sure enough it didn't have any disc drive!
i had a CR-V which had a really great electrical issue where it would drain the battery if you didn't start it every day. The dealer suggested that i should have somebody go to the airport and start the car for me every day while i was working out of town 0_o
a monopoly patent was literally a government invention. an actual monopoly does require the government. what you are talking about is called a "natural monopoly" in the literature. that would be a situation where there's only one seller for something like say water in a desert town. in that case you can have price gouging and such.
now, the important bit is the LEGAL ability to prevent competition. if there is a natural monopoly on water, and the seller decided to start charging obscene amounts for water, those extreme profits would normally induce other sellers to enter the market. except when they are legally prohibited, we can expect that a natural monopoly will not last if what we call "monopoly rents" are extracted.
so you see, a true monopoly requires legal force, eg the state.
but almost no two libertarians will agree about those things. if you think there is only one "blessed" or accepted viewpoint on those topics, you've been duped.
for example on the rights of kids. there will be somebody who will argue they fully own themselves and parents are never allowed to hit children or otherwise harm them. then there will be some idiot who argues that because babies are helpless and the parents made it, that the parents "own" the child until some point and can do what they want with it. other libertarians will have even more differing viewpoints.
private keys, etc