How to enable SSH via terminal without sudo?
I would hope not since that would be a huge security vulnerability in the OS. Remote executable access without end user approval would be a highly exploitable vulnerability in the OS.

That being said, I wouldn't presume it's not possible but if it were possible, I would expect that to be a very closely guarded secret and not shared publicly. 

A "white hat" might disclose this to Apple, the vendor to fix and then announce.

A "black hat" might develop the exploit and then sell it for millions of $$ or weaponize it for their nationality / social group of choice.

At this point, the definition of who is wearing the white/black hats is going to be highly controversial and subjective. About the only thing everyone can agree upon is all hat colors gain/lose social status having found and chosen how they disclose.