Personally, I think it’s most likely that he’s composed of many people. It’s a bunch of stories which all got attributed as one person, which isn’t uncommon. Personally, though I’m far from an expert, I think there wasn’t a singular Jesus figure who actually existed, but rather a story of a figure named Jesus that rose from stories about other events.
Like you said, it’s almost certain that something was happening around that time. In fact, there are many more Messiahs who were mostly forgotten. I just think it’s most likely that people told stories and those stories all merged together into another larger story, which then became the story of Jesus.