Why the Royal Navy preferred separate carriers and cruisers

Did the Royal Navy study flight-deck cruisers in the 1930s?

Yes, but it concluded that separate carriers and cruisers working together made better operational sense.

The Royal Navy examined several ways of combining aircraft and cruiser functions during the 1930s. It ultimately found more value in letting a carrier concentrate on flying and a cruiser on surface-warfare duties. Operating them together preserved aviation support without forcing both roles into one compromised hull. The abandoned hybrid studies help explain the later carrier-and-cruiser task-group model.