There is a fundamental difference between scientists and flat-earther you forgot to mention:
Scientists know they are most likely wrong.

Also there is also a fundamental difference between science and the flat-earth conspiracy theory:
Science works throughout our universe, wether it exists or not.
Flat earth only works if everything scientists and even our own eyes tell us is wrong. And even in that case there could be infinite other possibilities than flat-earth.

If I go to China and tell you there was a building shaped like a purple elephant, maybe you believe me.

I would believe you if you brought a high-resolution picture.

It's science when you can observe and verify it.

You can actually observe the distance to the sun, earth's rotation, earth's radius.
You can even observe the thousands of satellites(like ISS, Hubble, …) brought into orbit.

But it wouldn't surprise me at all if what's actually out there is different somehow than what NASA portrays to us in school.

I never saw someone from NASA at my school :D
Also take a look at my first paragraph…

When traveling to the moon and thru the cosmos and everything is accessible and you can see and test it, then you can call it science.

How will you differentiate VR and reality in that future?
At any point you could say: "No I don't believe!", but don't you think the assumption, that what we see is real and what many others also see is real, is the most important before you can do any form of science?
Trusting your senses versus trusting thousands of other human, who have a far better understanding of science than you will ever have. The latter seems to me much more reasonable, as you know the first can be really easy fooled(called a dream).

For all you know I could just be a computer program. Why do you still believe I was a human, as you certainly do, otherwise you wouldn't waste your time with that post?
That's essentially the same dilemma you have with science, but still you judge different on this one.