The point is that you are asking the wrong question sort of. If we only accepted physical remnants of someone or their life to prove they exist, Jesus wouldn’t be the only one we would have to throw out.

Not to say I know how to prove stuff historically, it does sort of seem like magic sometimes. If we found out today that carbon dating was off by a magnitude I would not be shocked, so that’s all the faith I have in it due to my bad understanding of it.