> Wouldn't take very many at all, we've now learned these past four years (and even the past 2 months). All you need are drones, that are pennies on the dollar cheaper than trillion-dollar militaries.

You make an incorrect conclusion which is unfortunately both quite popular and incorrect among westerners who read two and half editorials about Russo-Ukrainian war in some NYT/WAPO/whatever and think they now understand modern warfare. The reality of the situation is that drones are a very useful tool, but any side achieving actual air supremacy would result their fighters and bombers cruising over frontline and enemy towns on low altitudes taking out any high-value targets at whim. The situation would be similar to boots-on-the-ground phase of The Iraq War, resulting one of the sides to rapidly gaining ground and winning the war. Keep in mind that the cited "40k per-hour" price is quite cheap compared to per-hour operation cost of any kind of big ground force.

In fact, last thing US wants is to be in Russia's shoes unable to meaningfully advance into the territory of by all measures much weaker enemy.