While I see your point about avoiding "junk miles" and the benefits of "sweet spot" training, I'd argue that low-intensity sessions still have their place in a well-rounded cycling training plan. They can help build endurance and aid in recovery.
Polarized training, when done correctly, can provide a balance between intense and low-intensity workouts. It's not about mindlessly including "junk miles," but rather strategically incorporating them to enhance overall performance.
Additionally, overemphasizing moderate-intensity rides could lead to overtraining and injuries. As with any training plan, it's crucial to listen to your body and adjust your routine as needed.
So, while "sweet spot" training can be beneficial, let's not completely dismiss the value of low-intensity sessions in a balanced cycling training plan.
