I considered myself a libertarian until I discovered a fatal flaw: all sides have to abide by it.
Libertarianism is essentially just the original form of liberalism that emerged in from about 1650-1900. Sometimes now called classical liberalism.
Another issue is that liberalism by its very nature cannot assert itself, as it is against its own ideology. At the center is the belief in the individual as an agent for progress. If only everyone is left alone, we are better off. Some people speak of muscular liberalism, but there is no such thing. You can't believe both that and rigidly enforcing your ideas. Liberals also tend to be flounderers who couldn't enforce it if they tried.
I think the reason liberalism worked (from a materialist perspective) during past centuries is because it was wielded by wealthy, high IQ elites who remained considerably tethered into traditional family and social life. That was derailed considerably in the period about 1715-1815, when things became very liberal, leading to the mess of the early 19th century and the latter Victorian period. They were also were not hampered by the constraints of democracy.
When liberalism is given to the masses, they don't create an 8th symphony, romanticist art or write a book that will be remembered for centuries. They splodge around listening to Skrillex, buy prints of modernist art and half-read a book on polyamory. And it is not just the plebs that are descending into below-low-culture, the elites are joining them and increasingly living in debased manner; see Malia Obama on pot on Bill de Blasio's demonic antifa-child; not to mention crackhead Hunter.
What began in a movement elites found uplifting, has descended into sacrificing the foundations that upliftment was built on. It's not possible to create materially uplifting works when you are living in a materialist society. In a materialist society, the primary aim of men is ejaculation. You can see such venerated by the university sexologists. The end result of liberalism is becoming an animal, controlled by material pulls, which will increasingly elude you.
My observation is that in good times 90% of people will act liberally, which is ultimately to destroy your surroundings in pursuit of a declining yield of material goodies. It is literally the same as drug addiction.
There are also very few people of genuine liberal temperament. In a democracy, there is no chance for liberalism. Liberalism could only be imposed, as rigidly enforced as the tax code. As soon as society stopped enforcing those rules, liberalism would end promptly.
Liberalism is also the precursor of the left. A left was not going to form against King Henry VIII or Louis IX. It weakens the foundations of society. As society opens up and looses its traditions. The new liberal classes become wealthy and use that to take control of society. With a materialist mindset and greater freedom in organisation and thought, it is only a matter of time before politics involved millions with differing ideas, and almost all ultimately tethered to material concerns.
Further on the above, it seems that liberals shift left in times of progress and right in times of decline. I think of this as apologetic (left-leaning) and unapologetic (right-leaning).
An apologetic is someone who generally believes in freedom, science, materialism and "progress". Yet they see the disparities between themselves and others and want to lift others up. I believe this is a genuine impulse of theirs. Enter people more of the ilk of Sam Harris and the Weinstein bros.
An unapologetic is someone who generally believes in freedom, science, materialism and "progress" and doesn't feel the need to appologise for wielding and benefiting from them. Much of the grifter, astroturf "right" are just unapologetic liberals. Enter Denis Prager, Ben Shapiro and others.
Liberals are a powerful group of people as they posses a number of traits in high quantity - raw intelligence, logical thinking, the ability to see the world as it is more than as they would like it, empiricism, observation, clarity and so on. This is a few percent of people and they are responsible for most of the material upliftment in all of history. Thus I don't know if it is possible for them to really work within a traditional framework that is the foundation of society and their very existence. They will always become more powerful than traditional rulers who they see as a constraint.