Dang. It's almost like determining someone's sex is hard to do.

It isn't about the quantity. Its about the quality.

The US keeps their reserve in Arizona but it isnt a quick, easy, or cheap process to reactivate a plane depending on how it is stored. We have pulled two B-52s out of storage in the last decade as replacements after a ground fire and a crash. One took 19 months and the other took 12+ months.

https://www.dla.mil/About-DLA/News/Energy/Article/957538/ghost-rider-in-the-sky-b-52h-departs-tinker-in-historic-flight/

https://theaviationist.com/2020/12/17/wise-guy-is-back-regenerated-after-10-years-at-the-boneyard-b-52h-flies-again-after-pdm-at-tinker-afb/

And to make Russian forces worry that any cargo container within a couple miles of a sensitive area could pull over and have a bunch of drones pop out of it.