Personally I'm not a fan of it. Even in transit, I often have a backpack with me and can read the paperback books I have just fine.
Plus, what's a better replacement to me, is just having the kindle app installed on your phone. When I don't have a paperback with me, I just open the kindle app and read from there.
Which arguable is even easier to carry for being in-transit than a small book, since people usually have their phones weith them.
Is it common where you are to print them with thin paper?
Those combined bible/hymnals are usually personal, not for multiple people, and they're most common among denominations that only use the 150 psalms and a small number of hymns on texts directly from the bible, although I do have one with the bible and the entire Liedboek voor de Kerken (from 1973). Normal hymnals usually used to be printed on normal paper here.