Lets take their intelligence. They have large brains and a highly developed nervous system. They can solve problems such as moving through mazes, opening jars, and have been recorded using simple tools. Some biologists claim they can distinguish shapes and sizes. They have been tested for both long and short term memory (suckers!).
With 8 arms and hundreds of highly muscular suction cups capable of gripping. We have evidence of the octopus playing. We are pretty certain that they "walk" on two of their arms, leaving the bulk of the free for tool use. In this video you see one able to manipulate this coconut making a trap door house out of it.
They will continue to evolve and its only a matter of time.
But they have no bones . . . .