The alternative may have been a gradual improvement of moral and ethical thinking, leading to the end of slavery, while retaining the benefits of civilization and its technological achievements. There were anti-slavery thinkers at the time.

Revolution and other types of civilizational collapse essentially never lead to a reduction in suffering or misery, as the 20th century attests. Inequality may be reduced, but that's just because every one is poorer.

But it's a moot point because slavery didn't end in 477.