> The opportunity cost of the Apollo missions were enormous, even if there were positive outcomes that spun out of it.

True, but if you're talking opportunity costs then I see Apollo, and the space race in general, as a great success story. They took the polotical atmosphere of nationalism, paranoia, one-upmanship, costly signalling, etc. and funnelled some of it into exploration, science and engineering at otherwise unthinkable levels.

It it weren't for the space race, it's likely the majority of those resources would be poured into armaments, military-industrial churn, espionage, corruption/lobbying, (proxy) wars, etc.