Muggy your lack of comprehension does not mean it is a fantasy. The evidence in reaching space flies over our head. Last night I saw a couple of satellites passing by and if I had sat down long enough I would see the ISS pass by as well. I have seen the ISS before on nights like yesterday, so I did not feel like seeing it again (also mind it would have been in the middle of the night). About a month ago I sat down to see the ISS pass by 3 times. I could follow it on one of those live trackers and sure thing, when the live ISS tracker said I could see it, I saw a bright light passing by in the night sky. About 90 minutes later again and then again about 90 minutes later I could see it again. It is right there for everyone to see.
The moon landing sites have been spotted by third parties, here from earth, and are verified. There is no reason whatsoever to assume the moon landings were fake. Same like jroa in another thread. "Maybe" doesn't mean anything. "Maybe" they have an agreement. Yes "maybe" the tooth fairy is real too.
Last time I flew in a plane the travelling time on the southern hemisphere were about the same, for a similar flight in distance on the northern hemisphere. The difference between rumb line and the great circle.
The seasons I experience and have witnessed are another thing which matches only with a spherical earth. Or some bizarre things were to happen with the sun and the stars, which would not follow a clear pattern. This which has been demonstrated by one of the round earth members here in detailed calculations.
The viewing distances from higher altitudes could only correspond with a spherical earth. The flat earth has explained it as atmospheric density, but at a higher altitude you look at an angle and you actually look to much more air. Think about it. A right triangle.
If you're on the ground looking at an object at the distance, you will be at C, looking at A. This side is 'b' (mind the capital letters), if you go up 'a', you will be at B, looking down at A through 'c'. 'c' is always the longest side.
The coriolis effect, which corresponds with a spinning earth and which has the opposite effect on the southern hemisphere, only corresponds with a spherical earth.
The fact we have twilight corresponds with a spherical sun. A flat, spotlight-like sun, means the light will just fade away and could not light up higher ground, such as this mountain range.
You say: "Imagine a universe where starlight travels billions of light years before it even reaches the earth for the first time."
It is not like we are lucky to see the stars. The stars have been around for long before humanity started to exist. The thing is, the light we see left the star a very long time ago, only reaching our planet after such a long time. Because the star has been around much longer, the continious light has been going on for a much longer period. By the way, the nearest star is 4 lightyears away. We look at the star as how it was, 4 years ago. It is like travelling on a ship across the ocean. You set sail from England and a week later you arrive in the US. You have been there all the time, but only when you arrive at the US others can see you. Light is no different, except it is continiously coming towards you. Like a long stream of ships reaching from the English coast to the American coast. Except that wouldn't be very realastic, you could imagine (there's the word again) how this would work for light.
Gravity is another proving thing of a spherical earth. Since gravity differs per region. Therefore the flat earth cannot possibily constantly accelerate upwards. Physically impossible.
The fact the sun, the moon, and other planets are spheres, gives us sufficient ground to believe the earth is as well. Why would the earth be different. Considering all the evidence I have given above, there isn't any reason to assume the earth is different, in fact, rules out any possibility of a flat earth.
I am not sure why you can't comprehend a spherical earth. There is no reason to even lie about the shape of the earth to begin with, because there is no gain from it. If they would lie about the shape, why not make it a pyramid shape instead? Thing is...the spherical earth corresponds with all our observations thus far.
There is plenty of more that proofs the earth to be a sphere. Just lurk moar.
As for my original topic. If you can imagine a sphere so big.....as a flat earth believer you should consider the earth being in fact a sphere.