I just found the option to configure the controls in game and saw that is possible to use the Touchpad and Analog Sticks for the sliders.
Is there a benefit in using them for the Sliders instead of L1 and R1? It looks like a disadvantage to me, because you would have to leave the Arrows and Buttons to use the Sliders (risky) instead of having your fingers in specific positions at all time (Left Index at L1/Slider Left, Right Index at R1/Slider Right, Left Thumb on the Arrows and Right Thumb on the Buttons).
Best Answer
Using the sticks/touchpad would be more similar to the arcade version of Future Tone (which I think came first). The arcade cabinet controls consist of the four buttons in a row and a slider bar on top. You swipe the slider bar for the arrows. So if you want to replicate that playstyle, you would want to use the sticks or touchpad.