The issue is the largest salvo size that the US can throw at China.
My guess is 200 subsonic cruise missiles maximum.
For comparison, the Shanghai region can likely scramble 100+ fighters with at least 600 AAMs.
As long as there is an AWACs to detect the missiles and coordinate the fighters, all those incoming cruise missiles should be shot down. And that is before we consider ground-based air-defence.
EDIT. Note China has a huge number of modern AWACs aircraft.
Right.
It's actually even more lop-sided. US only has a few options of launching large salvos.
One is a large strike packages of tactical aircraft. For most of the figher/attack platforms in US inventory, the combat radius would be sub-1000km. So they either need to be based off less than half dozen bases, or carriers. Realistically, they will not be able to get off strike package of even approaching 100, give all the other mission sets they will need to do for their bases / carriers, especially in terms of force protection.
A second option is to use large fleet of tankers to extend the radii, so a much larger number of bases, and put carriers further back. Of course this means that tankers would be well within detection range of ground based UHF and L-band surveillance radars, air based surveillance, etc. Thus easy targets for the likes of PL-17 and R-37, or super long range SAMs.
Yet another option would be to use penetrating strategic platforms. But there only 19 such units capable of penetration of air defences against peer adversaries, until a large number of B-21s come online in the 2030s. The issue is similar for using attack subs, they don't have the mass necessary until a large number of block-V Virginias with VPMs get commissioned. A different issue if they decide to use the converted Ohio boats with TLAM-D/E, which are outdated, slow, and easily detected.
Finally, there are some more novel options like Rapid Dragon, like using JASSM-XR, that usually requires a large contingent of slow and non-survivable cargo planes flying within the A2AD bubble. If successful at all, would be basically a single use surprise attack.