It's said a lot that the historical record of Jesus is unreliable (accounts written long after he lived, contradictory accounts, etc.). Well, it's not like we have cell phone records and search histories of other figures from the same time period. Are records of, say, kings or pharaohs or Socrates considered more reliable, or is it just that Jesus is a more scrutinized figure? I mean, I never hear people say that Socrates didn't really exist.
The primary documentary evidence for Jesus is all within the first century, and some of it is within a generation. Compared to other literary evidence from Graeco-Roman historical writing, this is quite recent. So the suggestion that accounts appear ‘long after he lived’ is not really true if we are comparing documentary evidence.
You don’t hear (well, usually) people challenge the historicity of Socrates because far less is riding on that question. Jesus is a provocative figure in the modern world and some people have vested interests in him existing, and others have vested interests in him not existing.
Comparing Jesus to kings or other rulers is not really an ideal comparison. On the literary level, the documentary evidence slightly favours rulers, but it’s not usually as contemporary as early Christian texts. But Graeco-Roman authors didn’t write history for the same purpose. In regards to other evidence, say epigraphic, archaeological, etc., there is far more evidence for Caesars, etc.. The reason that it’s not a far comparison, though, is that Jesus is a marginal figure in his life – from relatively low class, on the fringes of empire, with little to no political impact in his life. Jesus’ importance is only massive because of the influence that multiplied after his death. Compared to other rural Jews, the evidence for Jesus is incredible precisely because there is any, and because there is (relatively) so much of it.