From what I know, there are zero contemporaneous writings about Jesus. The only writings about Jesus' life, actions, and sayings were recorded decades later, likely in Greece, by almost entirely anonymous authors, or authors who claimed to receive their information third hand at best.
The only extra-biblical sources that mention Jesus, which are again decades later, merely record the fact that there were some Christians and describe some of the things they believed. Josephus' well-known passage about Jesus refers to him as "the Christ" which no Jew of that time like him would do, and uses language inconsistent with the rest of his writings. It is considered by most biblical scholars to be a later forgery.
I wouldn't go so far as to say Jesus never existed, but the severe lack of reliable evidence is a problem for Christianity, especially since you can see a clear trajectory of more exaggeration and more miraculous claims as the various gospels were written, the farther out in time you go. This chronological growth of the tale applies to the four gospels included in the bible, but also the other gospels that didn't end up getting voted in. It seems like I could extrapolate back to the source and have an entirely mundane story about a charismatic leader, like those we see starting random cults or MLMs today.
I think it's impossible to know who Jesus really was, and what he actually said and did. I wouldn't accept the sort of evidence found in the bible for any other kind of similar claims, and so I can't accept in there either.
Edit: I didn't watch the video, sorry. I just wanted to give my own take rather than react to it.