Thanks, that's an interesting take.
I agree Polin seems to undervalue (or just not understand?) what a publisher brings to the table, but I did get the impression he is trying to do this as an offshoot of his vlogging business more than "as a photographer" and for that, flying solo might have advantages outside the actual sales and publicity of the book.
Funny that you say people don't really buy art: the primary complaint from artists about the art world is that there's too much money in it. Lots of people buy art, and lots of people make art, and lots of people sell art: for at least these three measures, more people than ever have at any previous time in recorded history. But sure, more people don't than do.
There's also a big error/assumption from Jared when he covers why he is self-publishing rather than going to dedicated publisher in that he talks about the publisher giving "an $X thousand dollar advance" - this simply does not happen with photobook publishers, they usually just give you a certain number of copies of the print run to sell yourself.
Even with 1.3million followers Jared probably wouldn't sell the 2,500 copies he is talking about printing here - this is why people go the Kickstarter route as you're pre-selling and can print to demand (plus a few copies on top). People don't really buy art, very few people are willing to drop $50+ on a photobook.
A reason people do go to publishers is that they have the marketing clout to get your book into independent photobook shops, visible at photobook festivals, into award listings, featured in newspapers, online, etc. That's the hard part in self-publishing, and even established publishers go the Kickstarter route if they're unsure about the potential demand for a book.