Anecdotally, to me it's just more fun. It increases range by relying entirely on the regenerative braking and relegating the disc brakes to an "emergency" role. For freeway driving in traffic it's also more intuitive, since you don't have to balance coasting/braking and can just ease off the pedal more to slow down quickly. Muscle memory can definitely be hard to break though, when I'm in a hurry I sometimes forget to enable single-pedal and drive for a bit before I realize it. The car we have (Chevy Bolt) has a separate regenerative brake control as a paddle on the back of the steering wheel for use in "regular" mode, but it's awkwardly placed.