Iranians have used conventional optical tech. The promise of the F35 is to be detected late by conventional long range radar. They were never supposed to be invisible or quiet.
Granted that makes the stealth advantage very limited in terms of usage: coming from far away undetected. Then be very visible.
Besides yes, China claims they can detect them with their satellites network and a France military equipment maker is apparently developing a radar that detects stealth jets. So that advantage is apparently not going to last.