That video does not tell the whole story. If you use an OBD tool with an app, you can view live input/output of the 48V system. When I had a 2021 with eTorque before getting my EcoD, I drove around for a bit watching what the system did. When taking your foot off the accelerator and not touching the brakes, the system was idle i.e. there is no regenerative braking taking place until you apply at least a miniscule amount of braking pressure - this makes sense because coasting is the most efficient thing you can do once you're already moving. During regular cruising, with adequate charge, the system provided torque to aid the engine for short periods of time - it does this so the battery can drain to have spare capacity for regen during braking, and and also saves some fuel. eTorque plays a role in upshifts and downshifts - it provides smoother shifts through its direct control of engine speed and in turn saves fuel & transmission wear through rev matching by increasing engine speed during downshifts, and recaptures energy by slowing the engine during upshifts.