Lexington, Hood, and G3 answer different battlecruiser problems

Did Hood make the Lexington class outdated, and did the G3 make it obsolete?

No; the designs served different roles, and fleet numbers and operating pairs matter as much as a one-on-one comparison.

Calling one class obsolete solely because another looks stronger ignores the mission each navy assigned it. Lexington was an American first generation intended for reconnaissance, information gathering, and economic warfare. G3 emerged after many British battlecruiser iterations and was optimized to destroy hostile battlecruisers, though it could perform the other missions as well. Hood began closer to the reconnaissance concept and acquired greater battle-line capability during construction; one completed Lexington might lose to her, but six operating in pairs would present a very different operational problem.