An ideal regenerative cycle is

Regenerative Cycle: In a regenerative cycle, some portion of steam is extracted from the turbine and used to heat the feed water before it enters the boiler. This process reduces the irreversibility of the cycle and increases efficiency.

Ideal Regenerative Cycle: In its ideal form, regeneration ensures that heat addition takes place at a single temperature, which is the same as in the Carnot cycle. Thus, the efficiency of the ideal regenerative cycle becomes equal to that of the Carnot cycle operating between the same temperature limits.

Why not Less or More: The actual regenerative cycle in practice will always have some losses and hence be less than Carnot efficiency. It can never exceed Carnot efficiency because Carnot represents the theoretical maximum efficiency possible between two temperature limits.

Therefore: For an ideal case, the regenerative cycle is equal to the Carnot cycle.