The real issue back then was whether or not it was worth the bother to sail west. It would be like driving from Manhattan to Death Valley without being able to stop at a motel anywhere in between. A lot of trouble to get from a difficult place to one arguably worse.
They’d have advised in their Michelins, “It’s like Africa, only a lot farther away.”
The final item, which nobody ever really addresses while working very, very hard to turn Columbus into an also-ran, not-important, the Indians-were-here-first-and-besides-everybody-else-discovered America-first white-European male-hate-filled bigot ... was that Columbus was the first who actually DID something with the information.
He went, he discovered something, he CAME BACK, and he TALKED ABOUT IT to other people who then went, did things, and came back.
Doesn’t matter how many times anybody else floated ashore - if they didn’t come back and pass the word on; if they didn’t survive as a colony or family or tribe all the way to modern times, they didn’t do anything important.
(They might have “did it” (sailed over and “discovered America” earlier than Columbus) - which is nice, and should not be ignored in the record. But it wasn’t important, since they died wihtout affecting later generations.)