Once Taiwan is reunified, submarines based in Taiwan directly access the Pacific Ocean depths. Then there is no geographic barrier to PLA nuclear ballistic missiles submarines showing up off the coast of California.
You need to take Taiwan first.
We are talking massive conventional strikes here and PLAAN does not have the hardware for this.
Where are the thousands of bombs and missiles going to come from?
Your aircraft carriers are too few and no match for even US light carriers that can hold 20-25 F-35Bs.