Fifth generation fighter jets aren’t built for dog-fighting. They are stealthy, mesh-networked missile and bomb platforms.
Modern fourth generation fighters would be more than sufficient up close. Except that fifth generation fighters hunt in packs and none of them need to be pointed at their target to hit them.
A lot of sci-fi gets tossed around about 5th-gen fighters and stealth vs non-stealth is extrapolated onto everything.
If you're communicating, you are broadcasting your position to the enemy. That means you can be shot down.
If you're in passive stealth mode, you can't detect the enemy and they can't detect you until both sides are extremely close and that means a dogfight.
All of this also ignores the massive advancements in IRST and AI which can likely pick out subtle patterns in radar and other data that normal hard-coded algorithms cannot.
If the illuminating plane is not a stealth plane, then it'll get shot by the stealth plane long before it can detect the stealth plane.
If the illuminating plane is a stealth plane, then you've just traded on stealth plane for another. Even worse, there's a decent chance that your broadcasting plane gets shot down, the illumination fails, and the enemy stealth plane still gets away leaving you one plane less for no gains at all.
Modern fourth generation fighters would be more than sufficient up close. Except that fifth generation fighters hunt in packs and none of them need to be pointed at their target to hit them.