The Gripen has higher rcs than f-35 yes, but on the other hand it did not take >25 years and 300+ billion dollars to develop the Gripen NG so everything comes with a prize tag. With more advanced irs-t systems Non-stealth fighters is given the capability to detect a stealth fighter even at longer range, SAAB claims that Gripen NG can detect Stealth aircrafts at BVR range. We of course dont know the exact capability but it seems clear that stealth fighters have lost a lot of the advantage they had. Gripen also seems to have a lower IR signature than the F-35 so if ECM, radar jammers, IRS-T etc is added to the equation it becomes a lot more complicated.
But it's the same old debate, LM and supporters of F-35 claims that stealth is the only relevant feature of a fighter while others Like Boeing, SAAB, etc claims that there are ways to counter stealth. We don't know the right answer yet and for now it does not matter either, F-35, Gripen, Rafales etc is all on the same side.