Sociality is not the only (and probably not an initial) driver of the evolution of intelligence in animals. Ecological and particularly foraging competency in less predictable environments is another and likely more primary stimulator for intelligence.
Coordinating complex movements is another one that appears to drive intelligence.
Vulnerability in a hostile environment. Together with foraging and coordinating complex movement plans, it is hypothesized that predation pressure when combined with the loss of their shell drove cephalopod intelligence. Trading defense for agility and int would also have provided a competitive advantage when competing for prey.
Coordinating complex movements is another one that appears to drive intelligence.
Vulnerability in a hostile environment. Together with foraging and coordinating complex movement plans, it is hypothesized that predation pressure when combined with the loss of their shell drove cephalopod intelligence. Trading defense for agility and int would also have provided a competitive advantage when competing for prey.