The Israelis have released footage of shooting down two drones, so they have the first kills with the F-35. Obviously this was not against a maneuvering human pilot, but still important.
They also have multiple (unproven but everyone knows who did it) strikes against iranian positions in syria and even in iran itself, it is rumoured. The ability to be invisible to radar is an absolute gamechanger.
That just make it difficult to lock on with weapons. They are not invisible and any radar operator would tell you that if they would be allowed...
"...Stealth designs minimize an aircraft's radar signature, delaying and sometimes even preventing detection, but because of the physical requirements for tactical jets, stealth fighters can be easily spotted by certain low-frequency radar bands.
In fact, it's not even uncommon for air traffic control radar to be able to spot stealth fighters on their scopes. And we're not just talking about when these aircraft are carrying external munitions or fuel tanks, rather, even in full-on "stealth mode," F-22s and F-35s aren't as sneaky as you might think."
While you're not wrong that stealthy ≠ invisible, a proper mission design will render the aircraft effectively invisible to air defenses.
If you've got an active radar system you'll bounce signals off anything in the sky. Your ability to actually detect those things is based on the strength of the return and sensitivity/signal processing of the system. Big things can be detected hundreds of miles away, small things only tens of miles away. To protect some high value target you string together multiple radar systems to provide overlapping coverage. With enough systems you can have an unbroken wall of radar directing defending aircraft and SAMs.
Stealth lets a big thing (a jet) pretend to be a small thing in the view of an air defense system, essentially cutting the detection range of radar. This means your unbroken radar coverage that would work for an F-15 now has a bunch of holes because each radar can only detect an F-22 twenty miles out instead of two hundred. Your radar is also further compromised because the stand-off range of anti-radiation missiles is outside the range you can detect and intercept the jets carrying them.
Being able to see a stealth aircraft after it's fired a weapon to kill you isn't super helpful. A stealth aircraft can also fly through the artificial holes it made in your radar coverage and blow up the thing you're protecting and you only find out about it after the fact.
That isn't really how it works. Low observable aircraft flying in friendly civilian airspace generally have radar transponders turned on specifically to make themselves visible to air traffic control and prevent collisions. Those transponders are turned off for combat missions. And ATC mostly doesn't use primary radar any more so they don't even get skin paints on regular aircraft.
https://www.youtube.com/watch?v=AdSFEpqwA6Q