The problem with the term "imaginary numbers" is that it implies they are more fictional than negatives, irrationals, etc. This is misleading, but not because "imaginary" numbers aren't fictional.

They are purely the unhinged hallucinations of deranged minds staring at nothing until they see the patterns that make it up--just like every other number.

You've never seen a two. You've never felt one, or tasted it. You've seen two of something, but the only part that exists is a thing and a thing. The two is an aspect of your perception, and projection of your mind, an attempt by your monkey brain to find patterns because it cannot encircle the uncompressed vastness of reality.

Numbers are a model. That's all they are, a tool that we invent to cast shadows into the cave of our own mind. They're a description we apply to reality, but the map is not the territory. And imaginary numbers do a very good job of describing certain territories.