Back in the 1960s, NASA got men to the moon by careful and clever engineering -- not just blowing a snotload of stuff up until they stumbled on something that worked. I suspect that if Mr Musk had been in charge of the Apollo program, we'd still be ducking bits of Saturn V boosters to this day and, at the very best, we might have dumped a lone banana on the lunar surface.
Starship is a bust for so many reasons but one of the primary reasons is that it's built of the wrong stuff -- stainless steel.
As a result of this poor material choice, Starship can't be built light enough to meet its original design objectives because stainless has inferior strength to weight ratio. This means the Starship is either going to be heavy or weak. If it's built weak then we see the type of fuel-line and tank leaks that have been so common because there is significant physical deformation occurring under load. If it's built heavy then the motors will have to be over-driven to get the necessary performance and that means poor reliability and vastly increased risk of catastrophic failure.
Another significant problem with stainless alloys is their COTE (coefficient of thermal expansion). Stainless expands far more than aluminum when heated and that means huge bending stresses are created during re-entry when one side of the craft gets a lot hotter than the other side (despite the thermal shielding). Think of a flying banana -- oh yes, that's right -- maybe that banana inside Starship was the engineers getting the final word -- despite Elon's insistence on stainless steel being used instead of more suitable materials.
Remember, the Space Shuttle (the world's most successful re-usable orbital spacecraft) was made largely of aluminum -- not stainless. Remember also that although stainless has a higher melting point than aluminum, it's not that much higher and still well below the temperatures encountered during orbital re-entry so SpaceX would be far better off focusing on a decent thermal barrier than trying to "brute force" their way through the heat of re-entry.
Nobody else in the rocket industry is using stainless steel and nobody else seems to be having the problems that SpaceX is having with the Starship. All of SpaceX's other craft are built with more conventional materials such as aluminum and composites -- they seem to fly just fine.
Unfortunately, Elon likes stainless "ooohh... shiny!" so I expect this is just another example (like the Cybertruck) where a non-engineer tells good engineers what to do and the outcome is a disaster.
