Why were scientists hesitant to dispute and displace the ideas of ancient thinkers?

Disputing current thinking means going up against a lot of opposition, and in older times, one could get in a lot of trouble with going against the accepted thinking of the time

During the paleolithic, hominins grouped together in small societies such as bands, and subsisted by gathering  plants  and fishing, hunting or scavenging wild  animals. the paleolithic is characterized by the use of knapped stone tools, although at the time humans also used  wood  and bone tools.