do you know how far madagascar is from easter island? if you're talking about mediterranean and river travel, yes you're right. but the pacific ocean + indian ocean are utterly massive.
I believe more trade between China and the Mediterranean was transited via Indian Ocean trade routes than via the traditional Silk Road, though I'm hard-pressed to find actual statistics.
It's easier to sail to and from Madagascar to much of Asia than it is to sail to Madagascar across the Madagascar channel.
[0] - https://commons.wikimedia.org/wiki/File:Corrientes-oceanicas...