As of a week or two ago, the F-35 is being seen in a peer conflict as unfit for dog-fighting and will be relegated to drone control, if they ever figure the loyal wing man stuff out. Both the ju20 and the su57 will likely pact R7 missiles which outrange current US BVRs by 30-45 miles. The 35s cannon still cannot shoot straight. I think the ju20 mission is for AWACs and refulers, not to go head to head in dogfights. The 35s and others will have to guard the AWACs and refulers at least as a secondary mission
The 35 was meant and designed as a limited stealth bomb truck for Anti-Access to supplement the 22. It is not an air superiority fighter as the 22 was designed to be.
The yf23 initially cost more to maintain the the 22 which killed the 23 in the end for the cost conscious Brass
F35 was always intended for a Jack of all trades. Not as an air superiority fighter. That was the F22 primary role.
However it was to pricey. With less than 200 actually made and production lines shuttered for good. I wonder actually how many are flight ready. Replacement parts have to be hard to come by.
How long will the USAF be able to get replacement parts.