[sofixa]

> but the F-35 can survive on the modern battlefield against S300/S400 etc. just fine

I don't think you could possibly know this. NATO countries have S-300s and the F-35 was probably tested against it, but it's highly unlikely it was tested against an actual latest gen S-400 in fighting condition ( if such a thing even exists, Russian military readiness is dubious at best).

[greedo]

Any SAM can shoot down any stealth fighter or bomber given the right conditions. Stealth isn't 100% invisibility. The US lost an F-117 in Bosnia due to both poor operational tactics and a clever foe.

You do realize that the S400 is just an upgraded S300, right? Hence it's original name of S300 PMU-3?