And "the horizon looks flat" is not evidence for a flat earth.
Yes it is. To a real Flat Earther he must see and observe the world around him and that is what he knows. Everything else is left unknown.
You are misunderstanding the following said:
Well, I'll take easily repeatable observation over a blank assertion.
It is also true in order for something to become truth, it must be
shown. So if you want to convince me you need to
show me. I'd like to leave out rationalization and just know what I see.
What I am still struggling with though, and I believe true Flat Earthers are struggling with me that there are instances where people are trying to show something, but the so-called "Flat Earther" (not a real one) says: "I'm sorry, not interested. I don't care what you want to show me as I already know what you are going to show me and my conclusion is such and such." That goes against Flat Earthism. Knowledge can only be gained by experience, but this cannot be reversed as:
"I choose my experiences to control the extent of my knowledge." Another translation of this sentence could read as "I happy with being fat, dumb and happy and I am not interested at all in gaining knowledge."
The real Flat Earther would say: "I want to
gain knowledge by experience". So
show me.
That's why I think there are so many nominals. Just as Christianty unfortunately.