Crypto as I know it doesn't allow performing an authenticated key exchange between two entities without neither a pre-shared secret nor a trusted third party (CA) [1]. Anyone who promises anything like that is either selling snake-oil or hiding some requirement. DANE still requires trusted third parties, I'm not sure why it's better than the current model.

[1] There's https://en.wikipedia.org/wiki/Merkle%27s_Puzzles, but it's not really practical when you make it secure and not secure when you make it practical.