Some of this was the overall urgency of the 1960s space race, that people were motivated to cut through red tape and get it done, and I know it's also argued that modern safety standards and requirements around supply chain, real time monitoring, system redundancy, etc all complicate things and raise costs.

That said, it would be interesting to have someone really knowledgeable go over what it is that Artemis has and Saturn V didn't, and then break them down and assign each an approximate proportion of the cost delta.