I am just guessing here, but maybe it’s also about relative priorities? Like, for Americans the air force is critical, because they typically fight at distant places and their pilots are expensive; while Russians can come to Ukraine by foot or by tanks, and the lives of the poor conscripted kids are politically unimportant and their training was cheap, so just sending the footsoldiers will probably achieve the military goal (whatever it is) anyway.
I am just guessing here, but maybe it’s also about relative priorities? Like, for Americans the air force is critical, because they typically fight at distant places and their pilots are expensive; while Russians can come to Ukraine by foot or by tanks, and the lives of the poor conscripted kids are politically unimportant and their training was cheap, so just sending the footsoldiers will probably achieve the military goal (whatever it is) anyway.