There’s actually no mention of Jesus or the things he seemingly has done outside of religious texts

Of the sparse selection of texts that have survived over 2000 years, there are a number of Roman histories that mention Jewish Messiahs cropping up during this period up to and around the Siege of Masada, which ended the First Jewish-Roman War.

Past that you can play the "if you excluded..." game with Greek philosophers, Roman emperors, Renaissance artists, hell you can do it with US Presidents.

Everyone from Socrates to Barack Obama is "cast into question" when you throw away the evidence you don't like.

The fact that "Christians" as a religious movement appeared at this time, and that we have an abundance of visual art, transcribed texts, and even physical structures dedicated to him just never seems to matter.

Some historians think thus, that the workings of Jesus were just an allegory

This reminds me of the endless debate surrounding whether Shakespeare was a real person. It's flogged to death, because you can casually assert "the evidence was written by liars".