Most records of historical people from that era were written well after, Jesus’ records were actually comparatively recent.

the narrative outside of Christian religious accounts is very minimal

Narratives surrounding Roman leaders, etc, outside of Roman accounts would be very minimal also. If Jesus of Nazareth really was God, it would be expected that the first-hand witnesses would of course be His followers and those that were close to Him. We do have enough from external accounts to know that He was crucified, and those that knew Him said He did miracles, they witnessed it, and that He was worshipped as God and it was widely claimed that He rose from the dead, and His body was never found. And the same people who said they witnessed it wouldn’t recant it either, on pain of death. The movement exploded a bit initially, and this would have been with first hand witnesses still alive that people could talk to, and quite a large number of them at that.

Sure, there’s not really a specific smoking gun, but it’s actually quite a lot more plausible than you realise.