

Missile silos are sadly, ridiculously hardened. You may have to hit a single door with 10+ drones to get through.
Aircraft are perfect targets, since an aircraft must be light and cannot be hidden underground too easily.
Also, missile silos aren’t being used to attack Ukraine. Knocking one out would have no effect on the safety of people in Ukraine. Aircraft however, are used daily / weekly. Tangible benefit is immediate - less air raids, less missiles fired, less glide bombs dropped.
It would also be sweet if a shortage of radar planes occurred - Russia not knowing what’s happening in its airspace would allow Ukrainian long-range drones to reach where they must.
They have, but this does not look like a fiber optic scenario.
Guesses: either: