But all of those 12 launches happened in just 3 years, and cost a tiny fraction of other major spaceflight development programs.

For reference, SLS has been in development for 5 times as long, and cost 15-20 times as much, as Starship, and they still haven’t landed people on the Moon, which has been one of the stated goals since the Constellation program in 2005.

I don’t see how the number of failures matters if the end result still happens faster and cheaper than anything else.

Recent SpaceX IPO filings put that 'tiny fraction' at about 1/3 or 1/2 of SLS. $15B total investment with about $4-5B of that figure from US gov. Is starship more than 1/2 or 1/3 of the way to a human rated Artemis II style mission? The main reason starship costs less to test (apart from the SLS jobs program baggage) is because of design choices which prevent it from performing such a mission without significant further tech development.

'5 times as long' is dubious too. SpaceX claims to have been working on the design since 2012 vs 2011 for SLS. Ultimately though the start date of a complex program is not well defined, as early conceptual design stages can take years without leaving the drawing board. Government needs to put a start date on such efforts for legal/budget reasons, but a private company does not.

Also relevant - SpaceX has been given a lot of tech and expertise from NASA at a tiny fraction of the cost and time it would have required them to develop it themselves. Therefore, the costs of NASA programs like space shuttle actually includes some of the development costs of SpaceX.

Both programs pale in comparison to Saturn V, which was faster, cheaper, and more technically demanding at the time.

Moreover the two lost shuttles included human lives. Better to blow stuff up with demo payloads now before sending up large contracted payloads or worse human beings!