Huh? They consistently do so. Have you missed the bi-weekly bombings of Ukraine's infrastructure? You can't do that unless you own the airspace.
The Russians can and DO hit any target they want to. Ukraine's air defense isn't sufficient to stop the missiles or drones coming in.
They can send cruise missiles and drones.
These can only hit fixed targets because they are guided by the Russian species of GPS or inertial navigation.
This is not effective at interdiction of road or rail traffic. You can target a location, road or rail, say a bridge, but you cant target a convoy. And the Russians have targeted bridges, but apparently can’t hit them effectively with their cruise missiles, as they gave up. And for the most part road or rail damage is easy to repair or work around.
For effective interdiction you need real time targeting and attack, which means aircraft overhead, as in the 1991 “road of death” in Kuwait.
And that aircraft overhead thing is what the Russians can’t do.