You wildly underestimate costs. A F-35 costs 85m-125m. NGAD will likely cost similar and won't be affected by most forms of Jamming, unlike current drones which makes them useless. It's only sheer luck that drones work in ukraine due to the meme levels of shit that is the Russian forces. Drones cost around a quarter or less of fighters normally but can't be flown in contested airspace due to jamming with current technology.