When I started using Pomodoros, I quickly got the sense that I had never before actually understood what it meant to focus. For example, I learned that I don't actually focus on the task at hand when I'm listening to music. When my "honeymoon period" ended, I had learned what focusing felt like, and learned to turn "focus" on and off without the need of the timer.

So it may just be that Pomodoros serve a transient purpose - they are a process you go through, not a tool you keep using. At least this is how it feels for me.