I believe they are just talking here about the missing baryonic matter; not dark matter. Dark matter remains a mystery.

Yeah, not only is a big chunk of gravity unaccounted for (potentially dark matter), but also a big chunk of actual matter could not be observed.

While a valid topic for a lecture or handful of folks, missing gravity or matter at distances greater than we’ll ever travel are like missing white kids’ pictures being put on milk cartons in the 80s:

https://en.m.wikipedia.org/wiki/Missing-children_milk_carton

Part of the universe will remain unobservable, until we can bend space that far safely.

What about making liquid nuclear fission better instead?

Thinking about these concepts are what made systems like GPS possible.

Shitting on pure research leaves you not knowing what you don't know to a much greater degree.

The meaning of life is essential also. Feynman was curious. Where would we be if he obsessed over cosmology?

No, like the quest of understanding cosmology is one of the pillars of scientific knowledge that enables our civilization from an engineering perspective. Ignoring it stops real progress.

Also, feynman's Nobel was about blending cosmological concepts into quantum theories. If he didn't obsess over that stuff we'd be without a lot of tools we used for nuclear engineering, and I'd argue distributed computing considering how inspired by feynman's work Lamport is.

Lamport used EWD123 [0] as his foundation.

[0] https://www.cs.utexas.edu/users/EWD/transcriptions/EWD01xx/E...

Lamport took inspiration from many sources.