Hatzichronoglou, Thomas: "Revision of the High-Technology Sector and Product Classification", OECD Science, Technology and Industry Working Papers, No. 1997/02, OECD Publishing, Paris.
Page 7 specifically divides manufacturing industries (it doesn't address services) into four technology levels, high, medium-high, medium low, and low:
High technology: Aerospace, computers, office machinery, electronics-communications, pharmaceuticals.
Medium-high technology: Scientific instruments, motor vehicles, electrical machinery, chemicals, other transport equipment, non-electrical machinery.
Medium-low technoogy: Rubber and plastic products, shipbuilding, other manufacturing, non-ferrous metals, non-metallic mineral products, fabricated metal products, petroleum refining, ferrous metals.
Low-technology: Paper printing, textiles and clothing, food, beverages, and tabacco, wood and furniture.
Given J.S. Mill's wonderful definition of technology, 'the study of effects", there's little in human activity which is completely atechnological. There remains, however, much that is quite some remove from the cutting edge.
Yes, Netflix is a tech company. Eventually all companies that are enabled by technology and software become tech companies.
Even banking is becoming a tech industry.
Is Netflix a tech company?
Is a company that sells ebooks a tech company? What about scientific journals? Are they tech companies?
Is Instagram a tech company? What about ad brokers?