BTW, my dissertation used tons of all kinds of sources as well as raw primary level research done myself in the process.
I think my ref pages were more than 20 pages.
And as acting head of the Special Collections Dept of the Univ Library in my BA program . . . I dealt overwhelmingly in primary sources.
“I dealt overwhelmingly in primary sources.”
Then you should have known that the latest posting was not reliable or valid primary source material.