No, the entire point of a series-parallel hybrid is that it can offer the advantage of a series hybrid.

The Toyota Prius powerchain has two motor generators, and can take part of the ICE power from one and transfer it electrically to the other, remapping the engine RPM into more efficient power bands at the same time. It has a mode that can do this even when no power is being used from the battery.

It’s kind of a best of both worlds. They can avoid the extra weight of a full series hybrid, because they don’t need a motor generator pair that handles the full engine power.

Actually, power bands remapping is essential for the Prius to operate.

There is no clutch, there is no neutral gear, there is no torque converter. The ICE is always connected directly to the wheels with a fixed gear ratio on a planetary gear set. (Which improves transmission efficiency over a automatic/CVT gearbox, and actually reduces maintenance costs)

One of the motor-generators is on the 3rd input of the planetary gear. For the ICE to idle (during warm up, or when you have the heater on), the motor-generator much be spinning backwards at the exact same speed so that the wheels stay stationary.

Power band remapping can also be used for reversing when the battery is empty.