Because historically (and for the most part today as well), it costs money.


Sure, today stuff like ChatGPT and the somewhat older Google Translate exists, but that doesn’t solve the cost issue.


There’s a huge chance someone paid a good chunk of money for all the books you find dirt-cheap at a flea market, check out at a library or happen to find in your own house.


Printing physical books is expensive. Publishers also want a margin, and a lot of authors want royalties.


In the end, someone needs to foot the cost of printing, and you’d need to go through non-trivial talks with most authors’ publishers (sometimes just the authors themselves).


Then you need to arange for translation, typesetting and printing if you’re not doing it yourself. That takes both time and money.


And if you were to do all that yourself, it’d be a huge time investment, with a potential lawsuit if you don’t do those damn talks. So most just don’t bother.


Businesses are incredibly inefficient, even though dome are “successful” and have a lot of cash to burn. It’s usually such a publisher that has a manager eho wants to get his section’s metrics up to go cry to his own manager about how good he is that chooses to publish a new book. Usually such actions are guided by things like bestseller lists rather than reviews. Simetimes the publisher hires an agency to try to approximate the demand for such a book (even more money spent). Then they do the talks. This also costs money, and the result is also a cost of money (the royalties to be paid). Then comes translation, then printing, then distribution to bookstores, then advertising.


These are just the steps that come to mind. All cost money, and all the books you see when you enter a bookstore went through all of these steps. For a library, not as much did, but the vast majority did.


Sure, not every situation is the same, so there are companies that specialize in providing translations of well-known works or companies whose manager at one point said they need to publish 25 translations yearly (instead of one individual one), so they kind of “flood” the market.


That’s the long answer.


The short one is: 90% the economy and 10% human laziness.