When smart people work on hard problems this usually comes with positive externalities. Even when the tech ends up worthless the the engineers will have learned a ton. I don't think that having people work on technology that is ahead of its time is bad for society. I think it's effectively high budget university research that presents itself as a commercial endeavor.

How much does silicon valley invest into these doomed sci-fi projects annually? Many hundreds of millions at least. I suspect PhDs at a university could produce a lot more innovation at a fraction of the cost.

Given that the tech and people went on to be involved in future nav systems, yes.

I imagine all that work digitising the maps was used again and again for a few decades, and the people brought their hard won knowledge to newer systems