Given that already before the 15th century in Europe:
Why did Europeans not consider to explore the possibility of a route to East Asia passing by Greenland? At least to see whether there was some in-between lands with enough frequency to establish ports and stock up on food and water before reaching the destination.
The resulting route could of course be only open during summer, but it would be possibly faster than around Africa or through land.
Greenland and Newfoundland maybe were known, but mostly for Scandinavian people which abandoned Greenland probably around 1430. What was the point of sailing north to the empty land during little ice age? Also nobody knew at that time that Greenland is an island. Anyway, for example from Lisbon to Chennai in India around Africa it's ~18 400 km. Going through Panama Canal (built hundred years ago) it's more than ~30 000 km.
Another thing, people were thinking that Indian Ocean is inner ocean/sea, something like Mediterranean. So it was easier to find out if there is a way around Africa.
And anooother thing, one guy considered it to go near Greenland - Giovanni Caboto. Of course there were multiple people after him like Martin Frobisher, John Davis, James Cook and Henry Hudson but Europeans already discovered way around Africa and new lands in America.
Funny thing is that people in ancient times (I'm not sure right now but it was like 600-500 years BC?) sailed around Africa but from east to west because of strong sea currents.