There is little need anymore to buy traditional Catholic books, as many of them are available on archive.org for download.
I have to take the role of "Devil's Advocate" here ... in my humble opinion there is no substitute for physical books, especially those printed on acid free paper with tight hardback binding. An attractive dust cover is nice also. I appreciate the utility of digital reference works when, with certain platforms, one can do searches, set bookmarks, highlight passages, make annotations, etc., but I usually always want the hardcopy also. There is nothing quite like a physical book for reading or praying, and they are an attractive accent for any home decor. My cataloged library is at about 1,100 books, probable 70% of the collection, but I keep buying, usually at used book shops or Better World Books, occasionally from e-Bay.
Working at a funeral home, with Catholic services the priest or deacon always uses a hard bound or soft leather covered Missal or Ritual. At many protestant services the officiant shows up with a tablet or sometimes reads the service from their phone

, which hugely detracts from the dignity and solemnity of the occasion.
And don't get me started on videos, so popular here. I sometimes wonder if many can no longer read or write and can only understand pictures and voice overs

. I've often thought ... if St. Thomas Aquanis was alive today, would he still write the Summa Theologica or would he just make a bunch of videos like the Dimond Bros ... I'm pretty sure I know the answer.