If the F-35 is so blindingly good (even on paper!!) why are they bothering to do that?
...possibly because Eurofighter is not a V/STOL aircraft?
Harrier can't go on forever can it?
Also the F-35 is slated as a replacement for the early-model F-18 for the US and to replace the USMC's fleet of AV-8Bs.
- that's why.