There is only one species of octopus that lives socially (LPSO are rare and incredibly intelligent but their lifespans are like 3 years)
Maybe your headcannon should be that apes did a "tower of babel" type thing to make all the octopus individualistic and unable to organize into a civilization
It's more complex than that. The famed octopus city[1] was populated by the gloomy octopus, a species which prior to the discover was believed to have been exclusively solitary.
Well the LPSO is the only consistently social octopus. "Octopus city" was actually 2 cities (the second one being discovered in 2016) and they were groups of about 15 gloomy octopuses. There are a couple of other examples of octopus sociality but on a species-wide level only the LPSO can be comfortably described as social
Almost all octopuses are cannibalistic but Abdopus have also been found living close to and tolerating each other
Actually, just like how among apes only one [sub]species has been known to develop sapience and civilization, could there be one particular species among octopuses that is particularly well suited for [future] sapience?
Maybe your headcannon should be that apes did a "tower of babel" type thing to make all the octopus individualistic and unable to organize into a civilization