I’m not a historian, but Tacitus definitely mentioned Jesus’ crucifixion. Saying there are a “a lot” of source is an exaggeration, you’re right about that, but there’s basically no doubt that Jesus was a real, historical figure. (I’m not saying that you’re disputing that, I’m just still stuck on the guy actually thinking that Jesus wasn’t real.)

Obviously Christian sources can’t be taken at face value, but there’s enough corroborating evidence - be it archaeological or written - that proves that at least some of the things in the gospels are based on facts, even if it’s certainly embellished and a lot of it likely just made up and/or warped over time.