The "move" from an agricultural economy to an industrial economy didn't end agriculture being a significant part of the national economy; agriculture just lost relative share of GDP. Similarly, the "move" to an information or services economy isn't necessarily going to eliminate either agricultural or industrial work. China, for example, has its tech giants (Tencent, Alibaba, etc.) but it also has vast industrial capacity (e.g. Shenzhen) and agricultural capacity (e.g. the largest pork production in the world). American education deciding to push children towards information-economy jobs that were a poor fit for their talents, neglecting classes like shop skills that were once common, was a mistake and certainly not inevitable.

"move" absolutely did move a lot of workforce, since farmers are much more productive, not as much help is needed.

A lot, but not all. The problem is that educational programs focusing on agriculture and manufacturing skills were eliminated in many school districts, rather than simply downsized to make room in the budget for information-economy education. By not offering these options at all, many children were pushed to positions that they were ill-suited for, often resulting in professional failure at best and at worst, large college debt that they would not be able to service without the expected parallel high-salary professional job.