Google was one of the first to use containers for data centers. Then Microsoft. Then there was a flood of companies using containers in data centers. Google doesn't mention shipping containers and the term containers has been taken over by software containers.
Why were shipping containers so much bigger impact than data center containers? How big was the impact of shipping containers? An economic study covered by The Economist says that shipping containers account for 320% growth in shipments in its first 5 years and a 790% over a total of 20 years from the start of standardization in 1966.
The shipping container caused the manufacturing, distribution, transportation, and end-users to change their way of thinking and operating to be faster and lower cost.
An example of where data center containers didn't work is Microsoft found it was slower to use its ITPAC containers and is reducing its use.
The same article mentions Microsoft transitioning to standardization like OCP.
So why did shipping containers succeed because of the breadth of its standardization created an ISO standard. It was 10 years from the start of the metal shipping container until there was international standard.
Basically, the data center industry was a "concrete" thinker in using shipping containers. The shipping container in transportation is "abstract" as a standard that has wide adoption in the industry and there were many other little things that happened like a unique ID standard for identifying each container. Cargo loading shifted from a decentralized in the bowels of the ship wedging cargo in what appears to be the most efficient to a central planning operation of how to plan for ports of call, refrigerated containers, hazardous material, etc. Computer software was now applied to the detailed planning of container movement from manufacturer to rail/truck to port to ship to destination port to rail/truck all with a container never being opened.