How significant is the destruction of the windmill in Animal Farm?

It was very significant as Napoleon used the destruction
of the windmill to his advantage, accusing Snowball of sabotaging the windmill, thus
causing it to collapse,  blaming all the bad things that had happened to the farm
squarely on Snowball's shoulders. Those who were at first fiercely loyal to Snowball had
to back down, in fear of further backlash. Also, the animals had to work even longer
hours carrying rocks up the quarry to rebuilt the damaged windmill, so they had lesser
time to rest.

Next, after the destruction of the windmill,
came Napoleon's rule by brute force- rule by terror. He was very suspicious, and was
very cold-blooded, killing all those conspirators who opposed his rule and his
totalitarian control. By then, it can be seen that Napoleon had completely disregarded
the Seven Commandments, one of them saying that animals cannot kill other animals. When
the hens rioted, they were killed for their resistance. But, an exception is that some
animals were coerced into confessions- crimes that they did not commit but was forced to
admit, and later, the dogs slit open their throats and they died on the spot. This
largely shows the dark nature of Napoleon's character and shows how power-hungry and
ambitious Napoleon was, to remain a foothold in the farm and maintain order and security
in it.