As noted at the beginning of this article, the F-35 is designed as an 'affordable stealth' counterpart to the F-22 Raptor air dominance fighter, one that can share "first day of the war" duties against defended targets but can't perform air-air or air-ground missions to the same standard. Its air-air combat flight benchmarks are only on par with the F-16, it has a single engine instead of twin thrust-vectoring F119s, and stealth that is less than the F-22A's but still represents an improvement over existing 'teen series' fighters and even 4th generation options like the Eurofighter.
