Form follows function, and there are only so many engineering solutions to stealth requirements. The F-117 is old, obsolete stealth technology, and everyone knows it. Which is why the “current” (or immediate past) generation(s) of stealth shaping (F-22, YF-23, PAK-FA/T-50, F-35, CALF, “J-20”) bear significant similarities to one another.
The “J-20” looks exactly like the CALF, just scaled up. The PAK-FA/T-50 looks like a hybridization of F-22, F-35, YF-23 and Su-27 engineering.