I believe that the earth is only six thousand years old, but that aside, for most of human history people didnt drive cars as well. This is a bandwagon fallacy and a tradition fallacy. Who cares what ancient people thought of the earth. They had limited resources for the most part. What evidence you have that the earth is flat (besides Kansas)?
I don't even know where to begin with this one, but that's never stopped me before, so here we go.
How is it a bandwagon fallacy?
How is it a tradition fallacy?
"Who cares what ancient people thought of the earth?" Well, we are trying to determine if people got from place to place just fine for the majority of human existence. Are we to exclude anything before Antiquity because you don't care about them?
Look, this one's simple. Just say, "I'm sorry, I didn't consider the vast time periods involved. People did think that the world was flat for a long, long time (regardless of the exact length)." It's all right, you dropped the ball on this one. I can't speak for other flat-earhers, but I'll respect you much more if you admit your error rather than spewing these, frankly, ludicrous arguments. Admitting fault won't make the earth flat, but it will considerably help your platform.