The targets of Ukraine's attack don't make sense to me.

Ukraine targeted Russian strategic delivery systems in it's brilliant shitting(typo I am keeping) container attack. It was awesome, that's not what I am here to talk about. I get the what's and how's, but not the why.

Ukraine spent significant "attack capital"( I am sure there is a better phrase) on this. What I mean is they probably could have used this tactic to attack almost anything- potentially Putin himself, if done at the recent "victory day" parade. This is something that will probably work again to some extent, but the unexpected first appearance of this is something that I am sure the Ukrainians did not expend lightly.

So why use half of it targeting strategic delivery systems targeting the United States? If my understanding is correct, many of the drones went after strategic bombers in the eastern end of Russia, whose primary target is the United States, including a submarine base? Surely there are targets more relevant to the war in Ukraine?

Ukraine's attack, as far as I can tell, was not an efficient use of resources- and I know they're smarter than I am. So what are they after? What is/was the intended effect? It almost seems like the intent was to threaten Russia's nuclear triad, and undermine MAD, but that just kinda seems farfetfched and fantastical. So why target bombers targeting Alaska? Looking for the logic here.