The benefit derived from laying many eggs by the octopus is that it increases the chance that more individuals will survive to maintain the population.
For organisms that serve as prey for another organism in the same ecosystem, the more their reproductive capacities, the better the chances of the population's continued existence in the ecosystem.
Since only 5% of the number of offspring produced by octopuses only make it to adulthood, this means that the higher the number of offspring produced, the higher the chances of more making it to adulthood.
More on survival rates in ecosystems can be found here: https://brainly.com/question/11387761