Digital - easier to carry and to handle while reading. Plus u can read on a phone/laptop in dark environments as well. However for reading on a plane, where I’m sitting in one place, I somehow prefer physical books as they’re less painful than looking at a lit up screen for extended periods of time.
I thought Nova was going the way of dinosaurs (i.e. there’s only one developer left to support it).
Edit to add: Unlikely that Google will do anything about it. What will users do - switch to iOS? Also, is it completely in Google’s hands, since stock launchers on third party devices such as OnePlus, Samsung, et al continue to work quite well.