The F-35 is stealthier than the F-22.
And this is what the Israelis are saying:
https://www.nextbigfuture.com/2016/04/israel-will-heavily-modify-their-f35.html
In 2012 Aviation Week article indicated that low radar cross section is a niche capability [aka stealth], and new sensor technology advances can make it less important. China, India and Russia are already finding weaknesses in stealth as they develop it for their own advanced strike aircraft. A senior Israeli Air Force official as saying (of the F-35) “We think the stealth protection will be good for 5–10 years, but the aircraft will be in service for 30–40 years.”
Even the Israelis think the F-35's stealth, which is better than the F-22's, is not good enough.
Here's what ACM Dhanoa said about the J-20.
http://www.asianage.com/india/all-india/061017/can-strike-pakistan-nuclear-targets-iaf-chief.html
“The J20 does not have full stealth capability. That way, the perfect stealth aircraft would be the American B-2 bomber, just look at its shape. So the J20 would not be invisible to our radars. Moreover, the new state-of-the-art technology fighters like the Rafale that we are acquiring would be able to detect an incoming J20.”
This is among the many reasons why the USAF believes the F-22 is no longer good enough in a 2030 environment.
http://www.af.mil/Portals/1/documents/airpower/Air Superiority 2030 Flight Plan.pdf
Threat capabilities are likely to advance along two major vectors over the next 15 years. First, traditional threat systems will continue to evolve and proliferate. Along this threat vector are advanced fighter aircraft, sensors, and weapons. While near-peers have most of these capabilities today, advanced air and surface threats are spreading to other countries around the world. Air superiority forces will face growing numbers of these threats across a wide range of locations and scenarios in 2030.
The second threat vector is a series of comprehensive capabilities with a less predictable impact on warfare. These include increased threat capabilities to negate our advantages in the space domain, increased quantity and sophistication of cyberspace threats, and air threats including hypersonic weapons, low observable cruise missiles, and sophisticated conventional ballistic missile systems. How, when and where these capabilities emerge is less clear, but it is certain air superiority forces will face many of these threats by 2030.
The Air Force’s projected force structure in 2030 is not capable of fighting and winning against this array of potential adversary capabilities.
Translation: The F-22 and F-35 are not good enough.
The J-20, F-22, F-35 etc are not as stealthy as it's made out to be. Or you don't want to believe your own ACM's words?
Yes, a small seeker can lock on to the F-22 as long as the Rafale can guide it properly towards the F-22. Seekers are really good at this, especially because they work at low ranges.