No offense; but in an ideal world you're right.

But, we don't live in an ideal world.

Unfortunately, we live in a fallen world.

Before I go forward, I want to note that this is strictly in reply to your comment without taking note of the video.

In the days of David and Goliath, a stone was used to save the peoples from the giant. (1 Samuel 17: 40-49).

In our fallen world, there will be wars and rumors of wars (Matthew 24: 6-14)...

Presumably, God knew there would be war; and, with war comes weaponry.

Lastly, while it will be wonderful when the necessity to protect ourselves from wild animals, and people wanting to do harm to the less-strong no longer exists; until that Great Day, I beg to differ with your comment.

Peace.