E-readers do a good job of bridging the physical book feel with technology. I was of the same thought that a phone would be enough until I held a Kindle in my hands. The first thing that popped out to me was that the screen was super close to a real book. I doesn't have that electronic screen look so it's much easier on the eyes. And you can change the color temp to make it even easier. It's also not silky smooth like a phone screen. There is a tiny bit of texture that makes it feel closer to paper. It's subtle but noticeable.

The second thing I noticed was that it was slightly bigger than the special edition colored paperback version of Game of Thrones I was reading at the time. The size being slightly bigger as one of the most comfortable books I've ever held in my life did change my perspective on e-readers being a viable replacement. Get a folding case that looks like a book and the fact that you're holding a Kindle disappears once you get used to it.

E-books don't take up that much space either. My whole collection is just over 1.5GB. Like 215 books in various formats. That might be nothing to someone who reads a billion books a year, but that's not me. My Kindle has 16gb of storage. Other models have much more and I feel like I would never fill it. I'm not gonna waste space on my phone for something I'm never gonna use it for.

I'm not tempted to stop reading halfway through a page to check social media when I'm holding my Kindle. I never needed to jailbreak my Kindle to put my own collection of books on it. I don't know if I'm lucky or if Calibre on Linux is just that good. Get one. Use it to read a short book. If it clicks you won't go back.