RANGER was hardly a carrier to take on the best the of IJN nor was the SARATOGA or WASP had the Japanese Navy been triumphant at Midway.
of course many dozens of brand new fleet carriers were all enroute to the Pacific after ESSEX was commissioned but had our Navy been defeated at Midway, the Japanese carriers would still be a mighty force with well trained pilots while most of our best fliers would have been lost so the pilots constituting these new air wings would not have had the lessons learned from the men who trained them who had been victorious at Midway.
In the end, American industrial might was going to crush the Japanese but the road to that final victory might have been a much longer and harder one if Midway had not gone to the US like it did