It could very well be an alternative. In your table, the figures do not convince me of its superiority.
By the appearance of the nail, I meant how it looks after the treatment, i.e., it hasn’t healed. As an additional problem, it is mentioned there that terbinafine discolors the nail. They intend to try reducing the strength. The risk there is that it won’t even work that well anymore, even though the concentrations are high to begin with. However, and again, no measurements have been taken from the nail matrix—where the nail grows from out of sight, i.e., near the surface of the bone—so it shouldn’t be compared to the concentrations of orally taken medication.
Why people use these not-so-effective treatments is not a medical question. It is perhaps more of a psychological-sociological one. Everyone likely starts their own experiment full of hope. Why do those perceived as women spend hundreds of euros on day and night creams for their faces year after year? Apparently, many perceived as men do too.