> At the same time, a parallel market in 3D printers for manufacturing was developing. These were printers that took up a whole room and cost hundreds of thousands of dollars.

Machines that take up rooms and cost hundreds of thousands of dollars existed a decade or more (probably 20 years, if I had to guess; patents) before hobby printers. I’ve not seen one retail printer that wasn’t based on the tech from giant commercial printers. And there is definitely tech in giant commercial printers that will never be retailized (laminated object manufacturing).