There are some fields where there are a real measurable advantages of physical books, essentially as an archive.

I can name two:

1) Chemical Engineering 2) Classics

In both cases the physical book may be the only place to find certain kinds of valuable info.

In the case of Chem E, I was told this by my father, also a Chem E, who said that some of these old books contained values and tests that were found nowhere else. And while a lot of that is available in modern form, not all of it is.

In the case of classics, I'm cribbing from David Butterfield here, who has a great book tour on YouTube where expands on this at length (4+ hours).

In the 18th and 19th century the level of education was higher and there were simply more people around who were working at the highest level in the field. Their speculations were written down in physical books and nowhere else. Many of these were valuable and showed new insights you won't find elsewhere else, especially for professionals in the field.

Here's an example. The copies that we have of, say, Homer, are copies of copies. Pretend for a moment that Homer actually wrote in English. We can imagine a line in the "original" (a copy of a copy), that says:

He of the stout quarrel chest said:

It kinda works - stout men quarrel, I guess. But you know what would work even better? He of the stout barrel chest. You can make a case that this was an instance of bad copying and should be corrected in editions going forward, especially if you can cite additional evidence.

Multiple this by the Greek & Roman corpus and all the possible permutations and you have a good reason to turn to those books that earlier writers thought very deeply about.