The results may be a day late and a dollar short (adjusting for inflation since 1939 or whenever), but Musk did actually get people to build spaceships, and his worldwide competitors there are floundering.
SpaceX is approximately half of mass launched to orbit, globally, including all other national and international space agencies. They are always free to trip up over Musk's hubris, but this hare isn't resting on its laurels or snoozing during the race — Starship (if successful) will eat the market for the Falcons. Conversely, quite a lot of the turtles (notably Boeing and Arianespace) are indeed resting on their laurels.
Other heavy/superheavy launchers can only catch up with and not surpass SpaceX until Musk disappears for whatever reason; getting past SpaceX without that probably needs a non-rocket launch system e.g. a Launch Loop or a skyhook/rotovator. Suspect only China can organise both investments and streamline the planning permission. Although at Musk's wealth level "buy sovereignty over a 10km wide strip starting on the coast of Mauritania and ending on the east border of Mali" is conceivable so even that's not a shoe-in.
Starship is still interesting even if they don't build a Mars colony. Or a moon colony. Or low orbit hotels. Or asteroid mining.
I think that even if they send some test missions on the Mars launch window 2 years from now, plenty will go wrong, and the same for the next window 4 year's from now. If Musk hasn't made too many political enemies to continue by that point, then they probably have a reasonable short for a crewed mission in the launch window after that, 6 years from now.
If SpaceX doesn't have a demonstration Sabatier process plant that fits into a Starship by the beginning of 2028, they've stopped caring about going to Mars. ISRU is too important, so even if they actually send any ships that way, without a Sabatier plant they would be no more relevant than the trans-Martian Roadster.
But this will make the matter more urgent for him, there is no reason for him to take it slow and steady, the opposite, he will push Starship hard. The next few years it will be vital for NASAs Moon landing. And after establishing a fuel depot in Earth orbit, which sounds science fiction now but is the plan for Artemis III, there will be whole new possibilities.
For example:
> 10,000 Teslas a Week [Link] 2,615 days since Elon Musk promised producton of 10,000 units a week by the end of 2018. (8/2/2017) "What people should absolutely have zero concern about, and I mean zero, is that Tesla will achieve a 10,000 unit production week by the end of next year." Elon Musk, quoted by Giovanni Bruno in The Street
They are producing now around 2 million cars a year which is four times 10K a week.
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> Teslas Are Boats [Link] 1,703 days since Elon Musk advised consumers that Teslas can safely function as a boat for short periods of time. (1/31/2020) "A Tesla works as a boat for short periods of time, as an electric car has no air intake or exhaust to block & battery/motor/electronics are water-sealed." Elon Musk in a Tweet
I mean, yes? Everytime there is a flood people are astonished about this. This videos from 5 days ago:
https://www.youtube.com/shorts/CEUq8PUAPWk
You could nail him on a technicality in that it is a submarines, but come on:
https://www.youtube.com/watch?v=UBwmAMNI9qk
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> Super Fast Starlink [Link] 1,315 days since Elon Musk promised Starlink customers their speed would double by the end of 2021. (2/22/2021) "Speed will double to ~300Mb/s & latency will drop to ~20ms later this year" Elon Musk in a Tweet
Some customers are hitting that:
https://www.reddit.com/r/Starlink/comments/1fh303p/live_in_t...
I had assumed that statements are added only after they've become false, so the 1st and 3rd of your examples would have been added on or around 01.01.2019 and 01.01.2022 respectively.
As to boats vs flotsam (the 2nd), I've already used up my thinking-about-Musk budget for the next couple of years, but since you've nerd-sniped: floating Teslas weren't cargo, so they're not flotsam; they weren't deliberately thrown overboard, so they're not jetsam; and as they haven't been abandoned, they're not derelict; but as I doubt they can navigate, unless they're displaying vertical lights or balls they're not conforming boats not under command, either.
Lagniappe: https://en.wikipedia.org/wiki/Ghost_ship#Historically_attest...
EDIT: closer to the boat/not boat boundary: https://www.flightglobal.com/airframers/us-regulators-given-...
EDIT2: so I watched the YT short; that's not even a boat, that's just a car wading.
Sorry, "boat" had left me imagining (1972) https://www.youtube.com/watch?v=vb9hh65iCik
He posted this several days ago: https://x.com/elonmusk/status/1837908705683059166
Nukes can fly, but for that transit you get far more opportunity to shoot them down. Bigger issues are "why are they bothering to target Mars, there's not much there" and "oh wait, that was a great place to stick a second-strike capability, Outer Space Treaty LOL, so of course it's being targeted".
Elon is not great at estimating how long tasks will take. He originally promised that full self driving would be complete by 2018.
But, yeah, Musk timelines are not something I would put a lot of faith in.
Snark aside, SpaceX may be thinking of MREs instead of growing food.
Christopher Columbus wasn't unique in believing the world was round, he was rather unique in his vast under-estimation of the distance to Asia. The only reason he survived is dumb luck that the Americas were about where he thought Asia was. All of his doubters were correct that he would die before reaching Asia.
Of course, this way, way far down the list of reasons not to take Christopher Columbus as a role model.