>>717379809
Learning a craft takes mentorship and lived experience. It takes literal decades to build up enough know-how, especially complex manufacturing.

Good story is about icebreakers. The US simply forgot how to make them. When the aging ones were set to retire there was literally no one in the business that knew the intricacies on how to shape the hulls.
Things of this nature is not just a matter of "researching it" and then knowing forever.