Origins of the Crisis
According to German-based Statista Research Department, some 80 percent of all goods globally are carried by sea including oil, coal, grains. Of that total, in terms of value, global maritime container trade accounts for some 60 percent of all seaborne trade, valued at around 14 trillion US dollars in 2019. This ocean shipping has become the arteries of the world economy for better or worse.
This is a direct consequence of the 1990's creation of the WTO with new rules favoring out-sourcing of manufacture to countries where production was far cheaper, that is as long as ocean transport was cheap. After China became a WTO member in 2001, they became the greatest beneficiary of the new rules and within a decade China was called the "workshop of the world." Entire industries such as electronics, pharmaceuticals, textiles, chemicals as well as plastics were transferred to China with then the world's lowest wages, for factory assembly. It worked because the cost of shipping to Western markets was comparatively low.
Comment: Another good summation of the supply chain and shipping crisis that is now occurring world-wide (just ignore the Covid-fear):