We live in a violent world, an unfair world, a scary world. And not all countries allow us to carry weapons for self defense.
Therefore, it is important that we learn martial arts whenever possible, that we may hold our attackers at bay when we are attacked by miscreants.
And judo is one of the strongest bases for self defense: it has given rise to popular offshoots like Brazilian jiu jitsu, but it continues to be a storehouse of knowledge...