The point of bomb trucks like B52/H-6 is that they're cheap and they don't get shot down because they're operating far back in permissive environment to deliver a lot of stand off weapons like missiles. They should be operating so far back that they can't be targeted and fired upon because yes if they are targeted they are probably toast. This isn't WW2, these planes aren't going to be flying directly over their targets and dropping large payloads of dumb bombs, everybody knows that would be a suicide mission. H-6 would be firing missiles from 300km back and so is much less of an easy target.
Also I'm not really sure what exactly you're advocating for. What is an "air superior interceptor"? This plane can apparently destroy SAMs, bombers, and fighters while carrying a large bomb load like B52? I'm not sure any plane in service right now can destroy SAMs, typically you try to maneuver so they miss not destroy them physically. Maybe some next gen plane with lasers or something but those aren't operational right now. You say this is cheaper than a bomb truck like B52 considering missiles cost money but have you considered that your super plane with all these advanced capabilities will probably cost way more money than some missiles?
Shoot what down? Incoming USAF planes? USAF is doing the same thing as PLAAF is doing, neither side expects to overfly the enemy and rain dumb bombs down like it's WW2. Both sides are expecting at least for the initial stages to be exclusively using stand off weapons. If you're talking about shooting down incoming missiles well existing planes/GBAD can do that, you don't need this "air superior interceptor". That's also not really the job of H-6/H-20 and there's no reason why it should be. Not every platform needs to be capable of everything.