The Chinese Hypersonic missile is uniquely tailored for its positioning in the Pacific. Its a terrible strategy for the USA, but a great strategy for China.
USA
doesn't need hypersonic missiles. Our enemies don't build "Iron Domes" or "AEGIS Cruisers", or "Patriot Missiles". Why would we create a Mach 5 missile that evades missile defenses, when our enemies are going with the "don't build a missile defense" strategy?
Our hypersonic capabilities are there only in case our enemies start developing missile shields of their own. Otherwise, our gameplan is "smack them with 100 Tomahawks", which are relatively cheap and very effective. In fact: the main problem with Hypersonic is that a singular Hypersonic missile is more than 10x the cost of a Tomahawk. Meaning, its more cost-effective to launch 10x Tomahawks simultaneously and hope that the enemy's defenses can't deal with it.
EDIT: The reason why super-expensive hypersonic missiles work for China, is because the USA has $13 Billion dollar Gerald Ford Aircraft "Supercarriers" floating around (plus the cost of all the airplanes and personnel on board). In contrast, China has no such high-value target. Any hypersonic missile we'd develop is more expensive than any ship China has ever made. There's no point.
There's different levels of stealth.
Our F35 probably will pop up on enemy radar screens, just like the Chinese counterpart. If they know that its coming, but if they can't shoot it down in time, the F35 will do its job and come home safely. Same thing with the Chinese counter-part, its not about being "secret", its about avoiding the "lock on" from modern missiles or modern CRAMs.
In contrast, F22 "stealth fighter" and B2 "stealth bombers" are aiming to be completely invisible to radar. Except their paint is so finicky that the F22 and B2 planes are a pain in the ass to take care of and maintain.
Any stealth capability means that US Patriot missiles will become less reliable at gunning down the airplanes. Normally, if we shot 100 Patriot missiles, we'd probably expect to kill 90+ enemy airplanes. However, if they have stealth capabilities, maybe our 100 missiles will only kill 50 of them, as the lock-on system fails spuriously. An F22 or B2 bomber would never get into this situation to begin with, but the mass produced airplanes have a fundamentally different mission...
Its more about a numbers game, cost-effectiveness and the like. Its not perfect stealth, just enough to cut down the efficacy of enemy weapons a notch.
China's Navy currently outnumbers the US Navy in terms of Ships.
View attachment 227483
That's 571 Chinese Ships,
vs the US Navy of ~500 ships (EDIT: My ship count was wrong, see below). China
already outnumber the USA, let alone Japan, and China continues to mass produce even more ships as we speak.
China will outnumber us with "lesser" ships. In the open-seas, I'm pretty sure the USA will beat China's Navy, but China's missile-force has been conducting some very troublesome tests. There's no guarantee that our Supercarriers will survive a fight against China's Missiles.
US Navy is better than Chinese Navy (for now and the foreseeable future). But US Navy vs Chinese MissileForce + Chinese Navy.... that's an open question.
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EDIT: I probably should post US Numbers:
https://sgp.fas.org/crs/weapons/RL32665.pdf
View attachment 227513
This is the combined forces of US Navy + US Marines. We got 355 ships vs the 571 ships of China. Now each of our ships are probably "better" than Chinese ships. Those Amphibious ships of the US Marines are practically small-carriers (F35B launch from them, while US Marines storm the beaches).
But as it stands right now,
we're already outnumbered by the Chinese Navy, and the Chinese Navy continues to build more and more ships. They're clearly planning something: either a bluff (is this just a diplomatic game to them??) or maybe a serious invasion of Taiwan.