Why did North Korea hit South Korea?

This is because it is conducive to the meeting between the leaders of the ROK and the DPRK, which have been deadlocked for many years. This conflict will not escalate, but it will also promote dialogue between state leaders, break the deadlock, and help to test the anti-India of other countries, such as the attitude of the United States, the backer of South Korea, to this incident, and then look at our attitude in China. The North Koreans used this skirmish as a test to pave the way for the reunification of North and South Korea and the future war. The above is purely my personal opinion. Give points if you think it makes sense.