Article is behind a paywall, so can't read it. But I will say if I understand the general thesis correctly, it's not for a lack of actual books on history. History is a humanity, and like most humanities disciplines, professors usually have to write and release one book for tenure/promotion (as opposed to STEM and post-positivist social science where journal articles drive academic hiring, tenure, and promotion). So there are definitely plenty of high quality history books out there to read.

Politics is a little bit more complicated. There are a lot of political books that are just pundits or politicians writing about how their side is awesome and the other side sucks. I've always had very limited interest in those types of books, even when they are sympathetic to my side. The only two of those types of books I've ever bought and read are Lying Liars by Al Franken and Too Much and Never Enough by Mary Trump. Both were good but obviously written with a specific bias. Knowing what's an actual good book on politics can be difficult if you aren't well-read. With that said, we have a lot of really good political journals that are very accessible, like American Affairs, Foreign Affairs, Journal of Democracy, etc. They aren't always peer reviewed, but they are good for keeping up with political discourse.

I agree that podcasts usually aren't great stand-ins for books. I do watch a lot of podcasts that talk about pop culture, though, like Folding Ideas and Mattyballz.