I’m not denying that, they definitely have, but fighting Japan along with the US makes it alot more difficult for China to win, they likely won’t be able to strike US mainland but it’s possible but they can strike Guam though with the DF-26 what they have around 250+ of according to US estimates so likely more. And possibly the CJ-20 if the H-6k is further out of mainland China what I find unlikely unless China has air superiority over the first island chain. I didn’t mention South Korea since South Korea is unlikely to join and would probably not allow US bases, and I didn’t mention the Philippines because their not a threat to China at all besides the US weapons thereLol. It's given fact that china has prepared to fight US, Japan Phillipines, and possibly south Korea. Maybe even India for a bit. Again lets be realistic. If japan or south Korea strike Chinese mainland, that gives China cover to strike their mainland as well. And I'm not sure they would like that exchange. If all US bases are hit in Japan and Korea, any collateral damage would make other countries think twice about housing US bases in the future in that region.
Sure strikes on US mainland will be limited but they don't need to strike US mainland. Eliminate most bases in first and second island chain, access denial for CSGs and supply ships and then it's tied.