Yep, you could argue that finding out after 2 months that an idea won't work is preferable to wasting 2 years on it. 'Course, then I went and repeated the process 8 more times, then decided that if there are no untapped market areas that can be filled by existing technology, it's time to spend 2 years inventing new technology. It remains to be seen whether that's a waste or not.
At some point you also have to apply the same logic to methodologies that you apply to ideas, though. The point of the Lean Startup methodology is to avoid wasting time implementing ideas that won't work so you can find a scalable, sustainable business model quicker. If your goal is to found a startup and all experience is that the Lean Startup methodology, in 2018, does not provide a scalable, sustainable way to do that, then you should ditch the methodology. Chances are you'll have to do your own methodology invention, though, because once a scalable, sustainable way to get rich becomes commonly known, it ceases to be sustainable.
(See also Bitcoin, which was a great way to get rich when nobody considered it a way to get rich, and then became a great way to become poor when everybody was certain it would make them rich.)