Because with a 15$ per year library card the authors won't be getting your money anyway.
Most books worth reading are illegal or are out of production,
and trying to find them for sale is a nightmare.
Usually any given book I am interested in purchasing is upwards of $400 because it is out of productioin and someone is scalping it.
Screw paying scalpers. Just download it. You can find a ways to access such resources on the main resources page here.
If I find a book to be particularly profound or impactful then I will consider purchasing it, but this is very rare.
In the event where a purchase would contribute to a dead author, the publishing company would just get the funds anyway.
If there were a way to wire funds directly to the family of the deceased author in exchange for the book then I would have no issues doing so.
If ownership is not an option then piracy is not theft.
If you are financially affluent enough to afford the luxury of owning physical copies of quality books (not slop),
then even the ownership experience is burdensome. Books take up so much space. It's another thing to maintain and take care of.
Book shelves are also quite expensive these days. My collection sits on a $40 chineseum industrial rack because
Book shelves are hundreds of dollars, unless I want sawdust junk from IKEA, which I don't.