Libertarianism fails because it attempts to achieve freedom, liberty, whatever you want to call it, rather than attempting to achieve the environment within which freedom flourishes.
This is the case for everything in life, if you want fame and money, don't pursue fame and money, pursue a skillset that will lead to fame and money. Yes, you might fail, but not so surely as if you aim only for fame and money. It's the same in relationships, pursuing the person of your dreams will probably fail, making yourself into a person that that person would want is more likely to succeed.
Libertarianism is perpetually the victim of unintended (but often wholly predictable) consequences.
Everyone should have the freedom to have guns! 30k/year are noticeably less free by virtue of being dead due to that freedom (yes, you could argue that the 20k/year of that number that are suicides are the freest of all, but I bet you wouldn't make that argument to their parents).
Everyone should be free to choose whether they have a vaccine. That directly infringes upon the freedom of the 2.7%* (~9 million) of the US population that are immunospuppressed. Are you prepared to state that 9 million Americans must stay in permanent lockdown so that the rest don't have to have the vaccine?
I wonder how quick people would be to forego vaccines and masks if they were going to be sued for contributng to the death of an individual? With gene sequencing of the virus that would potentially be possible.
If you "love feedom" then pursue a course that will give rise to freedom, pursuing freedom for its own sake is doomed to failure.