Libertarianism rests upon the answers to a few questions. Which is better: Freedom or slavery? Honest possession or theft? Truth or falsehood?
For any random individual the answer might be “it depends”. For one thing, define “better.”
Society prospers as individuals prosper. It is not right to make different rules for different people. This isn’t to say “one size fits all,” but that if something is true, it is true for all people for all times. If it is wrong for me to do something to you, then it is also wrong for you to do the same to me. It is universal.
One individual might be harmed by freedom. Either his own or someone else’s. Should he be able to infringe on the freedoms of other people to prevent himself being harmed? Yes, but only if those others wish to express their freedom by attacking or stealing. Should other people be able to infringe on his freedom to prevent him from hurting himself? No. That individual has the choice to exercise his freedom, or not, even if his choice would harm himself. It’s the same choice we all have.
If you claim slavery is better than freedom, that means you believe everyone should be a slave to someone else. Even the slave owners. That’s socialism. Yet, there are always individuals, those who make the rules they are willing to enforce with violence, who aren’t forced to follow those rules. Those who are most insistent on imposing this system on everyone else exempt themselves, either openly or in practice. Slavery is not best, even in the eyes of the would-be slave master.
A random individual might claim theft is better as long as he is the one receiving the stolen goods. If this were actually true, then as soon as the tables were turned, and everyone began taking advantage of the new morality and stealing his stuff, he would probably change his mind. Once again you can reverse roles to see through the propaganda.
Some people obviously prefer lies over truth. “Do these jeans make me look fat?” or “Do you think my sister is cuter than me?” Those are questions that are not always safe to answer truthfully. Not quite a “verbal grenade”, but very close. But are lies “better”? No. All things, even the truth, come with consequences.
So, for most individuals, freedom, property rights, and truth — the foundations of libertarianism — are preferable to the alternatives. Libertarianism is still the most ethical way ever discovered for dealing with others.