>issue is with developing the discipline. between a book and unwarranted doomscrolling

The issue is probably the unwarrated doomscrolling in general. If you do not read but go run, or clean or whatever productive thing that is all good.

If it is between you and doomscrolling, the doomscrolling seems to be a huge social issue and is affecting a lot of people. If you got an iphone set up limits? on android there must be apps for that. And just try to put it down particularly in the evening (screens and social media are IMO not good for sleep quality).

Are you reading books how? I think paper or e-ink ebook readers are very distraction free, but reading on devices with led screens much more dispersive and unfocused plus harder on the eyes.