The recent works are different; those that above MC (ie nobles, officials) want to enslave him/ treat him like a mutt and straight up kill him when he refuses to grovel and bow.
No emperor would feel safe, knowing a dude know bunch of op infos.
They already scared to death by family (even if innocent / persecussion sickness / to the point of getting depression and nightmares everyday) and you tell me that that they trust this random stranger that can invent dozens of good stuff and upgrade weaponry of whole army ???? bs !
I love it.