Our doctrine was built around aircraft, suppression of enemy air defenses, and then domination through missiles and total air superiority. We flew more combat sorties on Day 1 of Desert Storm than both of these nations have flown in two years of this conflict. Soviet (and by extension both of these nations) doctrine places emphasis on overwhelming manpower, artillery, and air defense.
We have an order of magnitude more combat aircraft of all classes than both of these nations combined. We have more AH-64s that are allocated just to training than both of these nations have helicopters in active service combined.
Ukraine is already giving Russia's AD systems a run for their money using our hand-me-downs from 30 or more years ago. Their aircraft have no stealth technology, ancient avionics, ancient targeting systems, last-generation anti-radiation missiles.
Russian AD systems stand zero chance against modern SEAD doctrine: we can see this in effect every time Ukraine uses decoy-based saturation attacks combined with cruise missiles. They simply do not have enough capable batteries to sustain a meaningful air defense when faced with a financially-superior adversary. We have tens of thousands of AGM-88 HARMs in stock: Russia has less than 2000 estimated S-300/S-400 acquisition radars.
Nuclear weapons are Russia's only real military trump card; Russia would cease to exist if confined to conventional munitions in a "peer" conflict. There exists exactly zero chance we end up in a Ukraine style meat grinder, we're deploying nuclear weapons long before that happens.
Also: Ukraine isn't engaged in total war and has no ability to wage it. The United States would (and has in past conflicts) engage in strategic bombing campaigns on absolutely every single manufacturing facility, every supply chain, in every complicit nation. In a US-Russia or US-China conflict, Iran doesn't get to sell drones or any other munitions without receiving 40 tons of JDAMs on their manufacturing facilities.