@AdamKnight
I believe some of the larger species of octopuses can actually snap the arm bones of an adult human, which is why you should stay away from them when scuba diving.
Bones aren’t necessary for pure strength. They do help us hold up our meat sacks properly (which is more of a concern for land-animals) but they also act as storage for calcium of phosphate, which are incredibly important for the ATP process in our cells.