First known person to present the idea was mathematician and philosopher Nicolas de Condorcet in the late 1700s. Not surprising, because he also laid out most ideals and values of modern liberal democracy as they are now. Amazing philosopher.
He basically invented the idea of ensemble learning (known as boosting in machine learning).
That essay is written by a political scientist. His arguments aren't very persuasive. Even if they were, he doesn't actually cite the person he's writing about, so I have no way to check the primary materials. It's not like this is uncommon either. Everyone who's smart since 1760 has extrapolated the industrial revolution and imagined something similar to the singularity. Malthus would be a bad example and Nietzsche would be a good example. But John von Neumann was a million times smarter than all of them, he named it the singularity, and that's why he gets the credit.
Check out "Sketch for a Historical Picture of the Progress of the Human Mind", by Marquis de Condorcet, 1794. The last chapter, The Tenth epoch/The future progress of the human mind. There he lays out unlimited advance of knowledge, unlimited lifespan for humans, improvement of physical faculties, and then finally improvement of the intellectual and moral faculties.
And this was not some obscure author, but leading figure in the French Enlightenment. Thomas Malthus wrote his essay on population as counterargument.
Butler also expanded this idea in his 1872 novel Erewhon, where he described a seemingly primitive island civilization that turned out to once had greater technology than the West, including mechanical AI, but they abandoned it when they began to fear its consequences. A lot of 20th century SF tropes in the Victorian period.
