The astronomical cost of the F-35 means that 1) we won't make that many of them and 2) we won't deploy that many of them.
The F35 is a peace time fighter. Same with the F22 and Eurofighter. Too expensive and complex for a proper shooting war. Even the Russian and Chinese offerings will need to be put through some simplification before they're ready to be mass produced on the scale needed for war.
If the shit really hit the fan (and somehow no-one dropped the bomb) then the current crop of aircraft will be radically redesigned to be cheaper and simpler to manufacture. WWII demonstrated that with Nazi Germany producing vastly superior tanks but because of their complexity, they were swarmed by cheaper, mass produced tanks. So in a shooting war against an enemy that can defend itself, the fighters we have dont matter as much as the fighters we can build.
The British had the same problem in WWII, their existing bomber force consisting of Blenheims and Wellingtons would be wiped out in 3 months. So they started designing new bombers, such as that thing they knocked together out of balsa wood and glue which became one of the most famous fighter-bombers of all time.