I didn’t post the text you quoted, but it was (probably) an accurate statement.
I almost entirely read the ancient sources and not the writings of historians, beyond Wikipedia summaries while searching around for more ancient sources, so I can’t conclusively say that historians generally agree that Jesus was a real person who was crucified. But I would expect them to as it explains what we see from what remains fairly well.
There are two things that I think we can be relatively certain on, with Jesus. He was baptised by John the Baptist and he was crucified. And I should note that I’m not using those terms as umbrella terms to refer to a baby baptismal nor a trial, being called the King of the Jews, etc. All of the specific details are up for grabs. All we can be certain of is the minimal declaration, that he was baptized at some point in his life by John, and he was crucified.
For both of these, we would tend to believe them because of all of the various competing organizations with different takes on the life of Jesus, where everything else changes, those two points remain constant. They’re true across the Orthodox gospels and across all of the Gnostic and Jewish-Christian gospels and writings that we have or are summarized for us by the early Christian commentators.
Much of the early writing, while “lost”, is pretty geared around stamping out heresies - Jewish-Christian and Gnostic sects. Much of what is in the Bible is Paul and others in his circle writing letters to discourage these heresies either by warning against them or clarifying the “orthodox” beliefs. And we know (though I don’t recall from where at the moment) that the “heresies” were writing similar works at the same time. We have a couple of names of works that were setting out to declare Paulian Christian a heresy and lay out the alternative orthodoxy.
Just from the Bible, it’s relatively clear that before 100 AD, there were already large schisms of belief, and that these groups were actively hostile to one another. And they’re not just hostile to other Christian groups, they’re also hostile to other groups which are descended from John the Baptist.
Overall, theories that Jesus was a fictional character made up by Paul don’t seem very plausible, because it seems strange for widely spread groups to take over a character created by him and then compete with him on it, so differently. Paul never gives any indication of knowing about or caring about John the Baptist, and it’s not clear why he would invent a past about prosecuting Christians if he’s the inventor of Christianity.
Similarly, it’s unclear why a group of Jews would create a fictional successor of John the Baptist. And note that early Jewish Christian/Gnostic works did not include the virgin birth, the trip to Bethlehem, etc. They largely stated things along the lines that Jesus was imbued with the power of John upon John’s death (similarly to how Paul claimed divine revelation from Jesus). Why create a realistic sounding leader, putting him in competition with Simon, Dositheos, and other competing successors of John? Presumably James the Just would have been the one to lead such an enterprise. But Jesus, minus the magical birth, gives no better story than James claiming the title for himself. They were brothers after all.
And this brings us to an area of historical criticism called the criterion of embarrassment. So whereas the interaction with John the Baptist is simply attested to from multiple, antagonistic groups, in the case of the crucifixion, we can go one step forward and point out that it’s a rather embarrassing eventuality for the early church.
As I noted, the description of what all occurred is not flattering to Jesus in any way. He almost literally cusses out a bunch of people at the temple, and topples over some pots of money, like an angry toddler. When the police come to pick him up, all of his followers flee the city and no one is willing to come to court to try and argue in his favor. After his judgment is proclaimed, the people of the city show no awareness of who this man - who supposedly has already crafted a number of miracles, affecting hundreds or thousands of people - and they choose to let some other bastard survive rather than Jesus - who they make fun of for his purported egotism.
Obviously, the Bible presents this all in the best terms. And the Christian argument that this was all some poetic end that had all sorts of religious importance seems to have been strong enough to pull a lot of people in (by which, I would assume that Paul is to thanks for the presentation, since he was the Man). But the reality is that someone like Mohammed or Joan of Arc can point to actual, verifiable results in the real world. Jesus barely had any impact outside of his immediate family, from what we can tell from the Gospels. If Paul hadn’t come along, it’s likely that Mandaeism and other religions descended from John the Baptist would have swamped out the same territory (in Jewish circles). Instead, one presumes that Paul’s success helped to raise Jesus’ cred among the Jews to start taking up Jewish Christianity and Christian Gnosticism.
Jesus’ death, at the hand of the Jews, is a really hard hurdle to leap. You’ve got to explain why the Messiah didn’t become the King of the Jews except by self-declaration. You’ve got to explain why God had him killed just a few months into his ministry. You’ve got to explain why, if Jesus was a Jew and the Jews killed him, that all that stuff in the Old Testament about the Jewish people being the select precious children of God is up on its head now.
If Jesus had become the King of Israel and rebuilt the temple, that would make everything so much easier. Instead, his end is sort of ignominious and sort of justified.
There’s really nothing good about it that an author would choose to work with if he wanted to create an ideal founder for founding the Christian religion.