Oh, the moral card. Morals are highly context-dependent and vary across the population and social classes. There is no consensus on the idea "reading books without paying for them is immoral". It may be - if the person reads all books by some author, can afford to pay, but never does, then it does smell like bad behaviour. But not everybody behaves like this.

Most books I download and read are some scholarly or technical stuff, where I read maybe one or two pages that interest me and then never open the book again for a year.

I could never get all the books from stone-walled library or buy them all. But fortunately I do not have to, they are all available in the Public Library called the Web, and using this is beneficial to me, and harmless to anybody else.