I don't know why you got downvoted -- but there is a definitely a visible artifact on that chart between 1939 and 1946, it's just not all that huge compared to modern deficit spending.
Right, but it should be huge, it was only significantly surpassed by the pandemic in 2020, which is a clue that these are unadjusted dollars, and so the graph lacks any explanatory power.
I don't know why you got downvoted -- but there is a definitely a visible artifact on that chart between 1939 and 1946, it's just not all that huge compared to modern deficit spending.