Why navies build before the ideal design is ready

Using Dreadnought and the Illustrious class, the discussion explains that a navy may order a workable design quickly because the strategic window is closing. Dreadnought mattered because Britain committed before rival all-big-gun projects could overtake it. The Illustrious design was already mature when the 1937 order was formally placed, so Britain could not instantly substitute a larger post-treaty ship. Its armoured hangar traded air-group size for protection within existing tonnage limits, while later Implacable and Audacious designs show the larger direction already being explored.