Would navies still have converted capital-ship hulls into carriers without the naval treaties?
Short answerBritain might prefer purpose-built carriers, the US case is uncertain, and Japan probably would not make the same conversions.
NotesThe Royal Navy might have scrapped Courageous, Glorious, and Furious in favour of purpose-built carriers, despite possible resistance from Beatty. That outcome reflects a preference for ships designed around aviation from the outset when treaty rules no longer preserve otherwise unwanted hulls. American attachment to the Lexington hulls makes their outcome less certain. Japan's historical conversions appear much less likely without treaty pressure, so removing the treaties would produce different answers in each navy rather than ending conversion everywhere.