Well, to specifically look at your patent example. Patents are one of the few things most types of Constitutionally focused Libertarian movements explicitly allow (U.S.C. Article 1, Sec 8, Clause 8).

But more generally, there are lots of things that only governments can do, that no free-market alternative can provide comparably, or can provide structure to where the non-government solution provides inefficient chaos.

People often use government mandated standards as the example. "Drinking water must have no more than x parts per million of y" and then provides testing and enforcement of those standards to ensure some minimal level of safety. And if some act of God means local drinking water becomes undrinkable regardless of efforts to clean, the government also carries out public awareness and warning campaigns and offers remediation guidelines.

Nothing stops private industry from providing better than those standards of water, but private industry generally doesn't. Given a set of minimal standards, private industry almost always targets those standards (but not better and of course there are exceptions). Now imagine what gets targeted when there are no standards and no enforcement of the standards? Is the water safe? or does it just not taste bad? I've been in countries where there was effectively no government oversight and the water tasted fine, but would land you in a hospital.

And there are many cases where private industry gets caught not providing that minimal standard and enforcement actions occur. Or industry that has nothing to do with water provisioning ends up contaminating water so badly that people's tap water lights on fire or whatever.

Industry self-regulation sometimes works, but just as often has been shown to not work well at all.