In that regards, stealth bombers with supercruise are the bare minimum for survivability in the face of 5th or 6th gen fighters. Or if the goal is to leapfrog into first place, then hypersonic stealth bombers are required.
Do you think a subsonic bomber taking off from China can destroy NORAD? Exactly.
I still think it's nigh-impossible to design a supercruising bomber that has global range and stealthier than the B-21 with current technology. Survivability isn't the only consideration as being detectable means the enemy can consistently force you to abandon your attacks even if they can't shoot you down.
TBH it is plausible that
the H-20 program has already been iced in favor of hypersonic, suborbital and/or orbital platforms, especially given the second Trump administration's visible embrace of emergent space based defense technologies, which is really an affirmation of SPACECOM/USSF programs and proposals that have been around for years.
Needless to say, China has been paying attention to these DoD developments.
This might have been a controversial statement a few years ago, but at this point there should be no contention on the fact that China is looking to surpass the US militarily, rather than to merely "catch up." This is evidenced by numerous developments that the US has no answer for, be it the Type 055 (Zumwalt doesn't work), DF-17/27 (let's not even get started), HQ-19 (no THAAD-ER yet), HQ-29 (KEI cancelled), or J-36.
China parameters defense mega projects on the bases of capabilities analogous and/or adverse US programs are intended to achieve, not what they actually achieve.
If that remains the case, the emergence of a subsonic H-20 or any H-20 appears increasingly unlikely.