In his book "Empire and Righteous Nation: 600 Years of China-Korea Relations," Yale University professor Odd Arne Westad cites knowledge and identity as two reasons for this. Members of the Joseon elite had a good enough understanding of the Ming and Qing empires that they were able to devise measures to remain independent from them. Also an important factor was the fact that the Korean Peninsula's people had long maintained an identity distinct from China.
The "righteous nation" in Westad's title refers to how the foundation of national identity for the people living on the Korean Peninsula lay in the concept of "righteousness," which had manifested among the "righteous armies" fighting back against foreign powers.
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The current fluctuations in the international order can be compared to the transition period between the Ming and Qing dynasties. At the time, the incompetent diplomacy of King Injo of Korea remained tied up in loyalty to Ming, inciting the calamity of the second Manchu invasion of Korea. The king ultimately suffered the humiliation of being forced to bow before Hong Taiji of the Qing dynasty.
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In "Review of Hong Taiji's War: Qing Invasion of Joseon Korea in 1637," a comprehensive study that even looked at Manchu materials, Seoul National University professor Koo Bum-jin tells a slightly different story. ...

In his first trip to China since taking office in May, [FM] Park [Jin] flew to the eastern port city of Qingdao to meet bilaterally with Wang Yi on Tuesday, as Seoul and Beijing are commemorating the 30th anniversary of the establishment of their diplomatic ties on Aug. 24. Park will be the highest-ranking South Korean official visit to China under the Yoon Suk-yeol administration launched in May.

One of the most pressing issues is the U.S. proposal for a semiconductor alliance known as the "Chip 4," also involving Japan and Taiwan, viewed by China as aimed at countering its influence. The foreign ministry has reportedly expressed Seoul's intent to join a preliminary meeting of Chip 4, expected to be held around early September, before deciding on its membership.