It feels like everyone has read The Lean Startup but hasn't understood the key message. I read it a few years ago, and I still ended up wasting too much of my time building something that no one wanted. Then I started advising other founders, and I see that most of them are still failing exactly how the book describes failing.
It apparently takes multiple exposures to the Lean Startup concept from different angles for people to get the core message. My own attempt to teach Lean Startup from another angle is called Bloated MVP [0]