Most of your arguments have been perfectly reasonable, but trying to argue about the value of a shipping tanker vs point to point minutes time transport is not. We're speaking of viable same day delivery anywhere in the world, or same hour in some cases. Obvious complete replacements would be air freight, military logistics, and much more. For stuff you're fine taking months, sea shipping will likely remain favorable.

Cisco is more comparable to something like NVidia in modern times in that their valuations was driven by success during a time that was already screaming bubble, and an expectation for that bubble to somehow never pop. By contrast the space industry hasn't even really begun yet, so the wager on SpaceX is more speculative in one way, but also much more likely to be stable in another.

China isn't likely behind - they are definitely far behind. They can't even settle on a design for their Starship. And similarly, I think one thing SpaceX has proven is that fail fast is the way forward. You can't just sit in a sim and send these things up. There's too many unknown unknowns that you can only learn by watching things go boom, a lot. There is no world where China just unveils their secret Starship clone and starts flying successful missions with it. Again that's something everybody tries (in no small part because it sucks when things worth tens of millions of dollars go boom), and always fails with.

SpaceX has never had any trouble raising funds when desired. I think the main reason they IPO'd is as a black swan hedge. We're at a major inflection point on many levels, and it's very conceivable that in 10 years the US' role in the global economy will have been greatly reduced. Obviously that $3 trillion valuation is largely funny money, but for now that funny money still functions well enough. But that's likely liminal. It's entirely possible, if not likely, that we're currently Japan circa 1989.