Why Courageous, Glorious, and Ark Royal were avoidable losses

Were the Royal Navy's early carrier losses caused by stupidity, incompetence, or ship design?

Primarily by poor employment, command decisions, and damage control rather than a general failure of British carrier design.

Courageous was used in a submarine-hunting role that exposed a valuable fleet carrier to exactly the threat she was searching for. Older and less strategically valuable ships such as Argus, Eagle, or Hermes were better suited to such experimental hunter-killer work. Glorious was then lost after failing to maintain the air patrol required by established procedure. Ark Royal's sinking added a damage-control and command failure, making the sequence a lesson in how capable ships can be lost through poor employment and execution.