Not everyone is wired that way. A failed workout for me usually isn’t as simple as a workout where you didn’t hit the proposed wattage/duration, it’s usually a workout where the body (or mind) isn’t working right due to poor preparation or other things outside my control. You can call it whatever you want, but it’s tough to eliminate failures along the way unless you are not testing your limits. Maybe it’s just a debate on terminology, but failure should be pursued/embraced/celebrated, particularly when it can be learned from.
While I totally agree that a handful of “core” v02max workouts is enough if you progress the power and duration, reduce rest intervals, etc., that’s essentially what many of the TR workouts are. If you start slicing and dicing the variables, you end up with countless ways to do “the same” 2’ v02max intervals.