These intentionally vague terms do have a purpose though - their inventors and early-to-mid adopters hype them up, write a book or two, sell few success stories

These intentionally vague terms do have a purpose though - their inventors and early-to-mid adopters hype them up, write a book or two, sell few success stories and that's it - they can now sell their services to the startups and large enterprises alike; then others start cargo-culting and vicious cycle goes on. This has happened with pretty much every vague thing in the tech: "OOP", "Agile" (SAFe and friends), "RESTful", "serverless", etc...