There are responses to every single one of these. Similar to Radioshack (3D printers, drones, Arduino, Raspberry PI), and Intel's (mobile, GPUs, foundries, AI) bankruptcies or "lost decades".
Distribute Books - They could have built a competitive distribution system by responding to what was an obvious aggressive threat. Amazon founded in 94', public by 97', buying book sellers by 98'. Four years, and Amazon was going International and buying book sellers.
e-books - Great. Sell e-books yourselves. Sell better e-books with Publisher extras.
Scanned catalog - Multiple responses. Legally inclined, lawsuits before it was all irreparably scraped (or afterward). Tech inclined, scrape your own stuff and make it available. Culturally or historically inclined, donate the texts to Gutenberg or a museum so the scraping doesn't get them much.
Authors have their own followings - Interact. "Hi, this is so-and-so from PRH, that's a neat idea for the author's work, and we'll discuss trying to work it into the next book launch." There's probably authors who follow authors, "Any of you wanna write a book?"
Cash advances - The cash advances are broke anyways. One of main points of the article. 70% of spending goes to 1% of authors. Try a slightly less power-law distribution. Maybe something a little less than x^60... PRH alone gave 55% of all advances in $1,000,000+ land. Have your own Kickstarters, or crowdfunding site. Arrange crowdfunding campaigns with marginal authors (for better author %). Work with fans directly so fans can put up the advance with pre-orders. Lots of alternatives to wringing their hands. (If Bates White Economic Consulting is correct, then 95% of money likely goes to 5% of authors).
What this article told me was the publishing industry has a bad case of "try to spend zero work, while making infinite $". 'if the platform is there for the advertising, then the spend might be lower.' 'Does the best selling author have the best marketing budget? No. Why? She's the queen of TikTok.' (she does her own marketing)
Ideally, the authors get their own loans from the bank, print their own materials, arrange their own distribution, put out their own marketing, and then we collect a vague value-add for putting our logo somewhere.