Why were many of the explorers voyages considered failures?

Many explorers' voyages were considered failures because they often did not achieve their primary objectives, such as finding a direct trade route to Asia or discovering new lands rich in resources. Additionally, they faced harsh conditions, conflicts with indigenous populations, and navigational challenges that led to loss of ships and crew. Furthermore, some explorers returned empty-handed or with limited findings, failing to meet the expectations of their sponsors and contributing little to geographic knowledge at the time.