Now imagine that setup with a bad tech lead who didn't know what they were doing. No oversight, no control, no feedback, no communicated goals to keep people accountable, etc.
Every single approach works when you have driven, intelligent people who all mean to do the right thing. The validity of an approach is only tested when those things stop being true and you need to notice and recover.
Well, no approach works when you have incompetent people doing the bare minimum and trying to subvert anything for their gain, so I don't known where you want to test anything.
The truth is that not all approaches work on your perfect scenario. Many are known exactly for turning competent cooperative people into incompetent individualists.
Every single approach works when you have driven, intelligent people who all mean to do the right thing. The validity of an approach is only tested when those things stop being true and you need to notice and recover.