Article uses the term bloc 60+ times without ever defining it other than to say it is small and black.

tldr: The report suggests they used powdered MnO2 to make fire starting easier.

The Wikipedia entry for MnO2 already references this article :-)

More proof that Neanderthals were as smart as, if not smarter than, _Homo sapiens sapiens_.

How is this proof of that? They just found something that worked through trial and error.

As opposed to... what we do?

Non-human animals also find random things that work for whatever it is they're doing.

Chimps eat a plant called Veronia that kills gut parasites. Does it mean chimps are smarter than humans and are also doctors?

Build a model, predict a particle and verify its existence?

That's a relatively recent development in terms of systemizing knowledge discovery. Prior, people literally just mixed stuff together to see what happened.