Paul did, and claimed to have met Jesus. So either he's a liar (hardly a surprising quality in a cult leader as we know from modern cult leaders) or someone resembling Jesus existed. I think the former substantially more likely given that the Jesus he claims to have met is absent from all contemporaneous documentation.

I'm afraid I'm I'd have to look up the literature about the historicity of Matthew, Mark, Luke and John and whether there is hard evidence to show that their purported authors were real people with those names who really wrote those texts. I don't know offhand. It's not a topic that's ever been of interest to me.

However I do know that all of the Gospels were written long after Jesus' supposed life and death. Hence they don't count as contemporaneous accounts even if you don't automatically discount them as historical evidence because they are religious manifestos and not historical records. They aren't eyewitness reports, they're collections of myths put together by people who weren't alive at the time the supposed events took place.