Why were many of the explorers jurnies considered failures?

Many explorers' journeys were deemed failures due to their inability to find the riches or new trade routes they sought, often resulting in financial losses for their sponsors. Additionally, some expeditions faced harsh conditions, hostile encounters with indigenous populations, or navigational errors that led to missed objectives. Furthermore, the explorers sometimes returned without the valuable discoveries or maps they had promised, leading to disillusionment about their ventures. Ultimately, these factors contributed to a perception of failure despite any potential contributions to geographical knowledge.