Libertarianism does not lead to fascism. That's directly contradictory.

But conservatives may leave libertarianism and head on over towards fascism.

The conservative and progressive movements are in a death-spiral, each periodically flirting with the authoritarian pole, then with the libertarian pole, but moving onwards, round and round the center. I was very aligned with progressives around 2000, very close to conservatives around 2016, and now I'm getting closer to equidistant again. And I don't think I've moved. I think they are moving.