the point is not the swing wing. the point is in having a plane with the role of medium ranged tactical strike with heavy munitions at relatively low cost (
vs
, about ~3x cheaper with inflation).
The F-111 wasn't made for the swing wing. The F-111 was made for a specific ground attack objective at a given production cost, build time and maintenance footprint, the swing wing was the method used to get there.
A JH-XX with ~3500 km combat radius, M1.6 max speed, integrated with 500-1000 km range cruise missiles, the LO characteristics of a J-20 and most of all, the
cost of a J-20, using 2x afterburning WS-15s with same TWR as the F-111, would be absolutely a formidable opponent and be able to fuck shit up while being extremely tricky to catch.
How do you catch something that goes the same speed as your planes, can see and launch at your ships from 500 km out, but you can't see it until you're 50 km in?
Unlike subsonics, you can't vector towards the launch point and hope to catch up to it because by the time you get there it has sprinted away yet still out of detection range of both radar and IRST.
And then even if you do shoot it down, there's 200-300 more. With the cost and dimensions of a fighter, it can be pumped out in fighter numbers (300+) rather than bomber numbers (~100).