There are YT channels that do flat-earth rebuttals. I just found out about this channel, and I don't know if it has been rebutted specifically.
The only rebuttal necessary on YT should be video of a ship sailing over the horizon. First the hull goes down below the horizon, then the mast, a foot at a time. If the earth were flat, it would just become a shrinking dot, but all would remain visible.
Beyond that, it's akin to arguing over flying reindeer. Waste of time.