I find the Chord Sequencer useful particularly in certain instrumentals, i.e. Sleepwalk, Steel Guitar Rag, Tuff, when it is helpful to have both hands available for bending notes and adding nuances.
You could do the same thing by pre-recording sequences, but then, unless you add markers, you are limited to the exact structure. Often when performing live, I want to extend a song or even end it quickly and the CS lends itself very well to that.
It's not an essential tool, but as I said, it is useful.
DonM