It is an actual area of research, mostly around scalability.

I don't know what happens in computer science departments, but you can watch Ethereum be developed in the open. They cite the research they're implementing.

For example: https://notes.ethereum.org/@vbuterin/proto_danksharding_faq#...

I'm not quite smart enough to follow all the cryptography, but there are a lot of unsolved problems being worked on. It seems that doing trust and accounting at global decentralized scale is trickier than chaining blocks together.