Here are a few prominent cryptographers in the 'cryptocurrency' scene with 'deep knowledge':

Matthew Green from John Hopkins University [0]

Zhenfei Zhang of Ethereum, Mina, Algorand blockchains who co-created the NIST post-quantum cryptography standard for digital signatures called Falcon [1]

Nadim Kobeissi creator of cryptocat now created Capsule Social [2]

Silvio Micali, Turing Award Winner for his work on Zero-Knowledge Proofs [3]

So, I'm afraid that there are some credible people like those above who have a significant and documented background in cryptography who are also working in the cryptocurrency industry.

[0] https://blog.cryptographyengineering.com/

[1] https://falcon-sign.info/

[2] https://nadim.computer/

[3] http://people.csail.mit.edu/silvio/

A lot of crypto nerds swarmed to this field because the tech is undeniably fun, and the whole space is rather interesting and is fun to play in. Kinda like it's more fun writing a multiplayer game than a singleplayer game?

I don't think most of these people are into cryptocurrencies specifically.

> I don't think most of these people are into cryptocurrencies specifically.

They are? Especially the creator of Algorand (a cryptocurrency) Silvio Micali. In his CV [0]

> "Scientific Interests, Cryptocurrencies, Blockchains"

At the bottom of his CV:

> "Technology Transfer: Algorand, Founder and Inventor of the Core Technology"

If that is not 'into' cryptocurrencies, then I don't know what is.

[0] http://people.csail.mit.edu/silvio/CV.pdf

Probably better if you are not a cryptographer. Because you have fewer inclination to write “your own cryptographic algo”.