I think it also comes from the Lang law, that prevents competition from different editions of the same book. In France, book are taxed at a much lower sales tax

I think it also comes from the Lang law, that prevents competition from different editions of the same book. In France, book are taxed at a much lower sales tax than other items but in exchange, there must be a single price for a given book (usually printed on the cover) https://en.wikipedia.org/wiki/Lang_Law https://en.wikipedia.org/wiki/Lang_Law So a publisher has to choose the format they are going to sell and the single price for it. It made most publisher favor the most popular soft-cover pocket-book format. Reference books, that need to be more durable, textbooks, photography books, comics, usually prefer hardcovers. (Disclaimer: I have no specific opinion on this law, I think it lowered the price of books in France and reached its goal in making literature more accessible but I have no idea about its detrimental effects on the industry. I have never seen anyone violently oppose it)