For the record, light can be bent. We see some stars which should hide behind objects straight in our line of sight. But those objects are sometimes very heavy, bending the light of the star behind it around its body, and we see the star anyway on a different spot.

But this is not what damocles meant I think. Damocles means that matter may not be able to bend light enough that it will never escape. I would disagree on intuition but have no arguments right now.

The best evidence supermassive blackholes exist is otherwise our galaxy wouldn't hold together. The center is supposed to have one big supermassive black hole.

Also if we replace our sun by an equally heavy black hole (disregarding the needed mass here) nothing strange would happen other than that light disappears. The earth will still revolve around our new black hole, and the moon around the earth. Gravity remains the same.