Why losing a small carrier costs less fleet capability

Why might a small carrier be treated as a more acceptable early-war loss?

Because it costs less capability, construction effort, and crew than losing a full-size fleet carrier.

Navies would prefer to lose no carriers. If a carrier loss is unavoidable, a smaller ship generally represents fewer crew lost and a less difficult replacement task. Argus is preferred as the loss over Courageous, and Hermes over Ark Royal. The distinction concerns the operational capability removed from the fleet and the consequences of replacing it.