Pearl Harbour failed, to an extent, because the planners were too focused on killing battleships. Had they destroyed the fleet train, drydocks, fuel storage and other REMF-specific areas they would have crippled the pacific fleet. But the planners were all old-school and though big guns = big importance. The USN showed them if you don't protect your merchant marine when you are a seaborne nation, you are screwed in the long run. The Germans showed it to the Brits, twice.
There was a plan years ago to turn 747s into massive air-launch cruise missile carriers (https://foxtrotalpha.jalopnik.com/why-b ... 1605150371). It never came to fruition, but a pair of these would be able to launch nearly 200 cruise missiles. Though as we have seen with naval missile strikes, a small flotilla is able to launch a massive cruise missile salvo. But what I haven't read much about was how long it took to reload those ships and return them to full strength. Which is always important in a longer war (though, in all fairness, when your opponent cannot shoot back it's not much of a 'war').
While not along the same offensive vein, there was a plan by the British during WW2 to build an 'unsinkable' carrier made of ice and sawdust and position it in the atlantic to provide air support for convoys. It never got off the ground, but it could have potentially been a game changer against the U-boats. Though usually every great idea has a great counter-idea by the other side, so they tend to equal each other out over the long run.