> They would require regular shipments of food and water from Earth
That's one of the core challenges techno-optimists like Musk constantly handwave and ignore when grandstanding about humanity becoming a "multi-planetary species". Yes, we can settle Mars. We could probably even do so with the technology we have today, certainly if we invest resources into further research and development with that specific goal in mind. But we can't do so in the political and economical landscape we have today.
We have a massive resource allocation problem here on Earth. We're overproducing goods because it's less economically damaging to destroy surplus products than to sell at cost or only produce to meet actual demand. We build for planned obsolesence and encourage wasteful competition between ten different companies owning a hundred different brands of the same product just to perpetuate an artificial demand via "FOMO". We're siphoning global wealth into the hands of a few people who waste our resources on superyachts like Bezos or actively prevent public infrastructure projects like Musk's attacks[0] on public mass transit. We're subsidizing legacy fossil fuel production and consumption instead of developing more efficient energy use and storage technologies. Meanwhile Russia suicide-bombed the European economy by invading Ukraine and now the US rapidly disassembles its decades old network of allies and trading partners. None of this is stabilizing let alone sustainable - and we need a sustainable human presence on Earth before we can build out a persistent presence elsewhere.
If Musk truly believed in making humanity a multi-planetary species to ensure the survival of our species, his main focus would be terraforming Earth, not Mars. Instead he sells visions of a future that only considers the extremely wealthy, with point-to-point rocket shuttles and hermetically sealed self-driving underground robotaxis. Just like Bezos uses his dildo rocket[1] for a girlboss publicity stunt after getting visibly upset when William Shatner had a genuine moment of realizing the fragile beauty of Earth and humanity[2] because Bezos' vision is to send all the unsightly refuse, industry and laborers into space so the rich and beautiful can have Earth to themselves[3].
But people like Musk aren't actually interested in making a multi-planetary species a reality. It's just a sexy mission statement that justifies their business ventures. He may actually believe in it but if he thinks that's what he's doing, he's not nearly as smart as people claim he is.
[0]: The Hyperloop concept was infamously pushed by Musk to sabotage the public infrastructure proposal of a highspeed rail network but this isn't the only example. A lot of his mass transit concepts boil down to "busses but smaller" or "trains/trams/metros but on wheels". When he first pitched the idea of FSD allowing Tesla owners to let their cars "work for them" as robotaxis, he also floated the idea that this could be used to pay for the cost of the car, which would allow Tesla to run a form of car sharing that offloads the actual risks and maintenance costs to the "owners" of the cars. Tesla's early vision also explicitly included the goal of making EVs affordable to the general public, which Musk no longer seems to be interested in.
[1]: Blue Origin's rockets have rightfully been criticized for being excessively phallic. While rockets necessarily have a phallic tendency, Bezos' rockets stand out for looking specifically dildo-like even by rocket standards. Given that there is no technical necessity for making it look this much like a dick and that the design hasn't been modified to make it any less dildo-like, the appearance can be considered deliberate even if we grant the benefit of the doubt and assume it wasn't originally intended to be so blatantly phallic - at some point everyone in charge agreed that the rocket should continue to look the way it does now.
[2]: There's a widely circulated video clip of Shatner having a moment and being interrupted by Bezos fetching and spraying a champagne bottle. Shatner stated that he went on the trip expecting to be overwhelmed by the endless possibilities of space because he had always been fascinated by it but that the experience had fundamentally changed his outlook by showing him the contrast of the vast emptiness of space and the vulnerability of Earth containing all that ever has and and ever will matter to him - an experience he apparently shares with many others who got to see Earth from space. Of course this isn't why Bezos took him on the ride and isn't a message Bezos cares for - the vapid girlboss soundbites by the more recent ride carrying female influencers is a much better match for his intented PR, especially the insistence on referring to the space tourists as "astronauts".
[3]: Although Bezos hasn't been in the news much over his visions (probably because when Musk did so he had a more receptive audience because there was a general pop culture of space optimism which largely seems to be gone now) he has floated the ideas of launching Earth's waste into space (presumably especially radioactive waste, which might be a bad idea if there's a chance of rocket malfunction) and of moving dirty industry into space to reduce pollution on Earth - the latter included the idea of creating habitats for the laborers, which had certain undertones.