Politics is the theory and practice of government. It concerns itself with how force should be applied in controlling people, which is to say, in restricting their freedom. It should be analyzed on that basis. Since freedom is indivisible, it makes little sense to compartmentalize it; but there are two basic types of freedom: social and economic.
According to the current usage, liberals tend to allow social freedom, but restrict economic freedom, while conservatives tend to restrict social freedom and allow economic freedom. An authoritarian (they now sometimes class themselves as “middle-of-the-roaders”) is one who believes both types of freedom should be restricted.
But what do you call someone who believes in both types of freedom? Unfortunately, something without a name may get overlooked or, if the name is only known to a few, it may be ignored as unimportant. That may explain why so few people know they are libertarians.