There is a difference between Libertarian as a political party and Libertarian as a political dynamic.
You need a governing force of some sort to maintain Liberty, otherwise someone just comes and takes it away. The American system actually managed to protect it for a good while, but has become broken. The Canadian system as well greatly protected liberty, but itself is starting to falter.
It isn't a failing of the political systems we have. Each system builds on the successes and learns from the failures of the last. We are due for another big reset, with the next step having better guidelines to protect from what has happened this time.
The Libertarian party in the USA is very Conservative, while Anarchists tend to be excessively Liberal. Both views are valid, we need the right and left to be able to debate with each other to keep each other in check and for real progress. Real political debate has not existed for quite a while though.