Earlier quoted context omitted.
Maybe, but many people read tweets and novels, just as many people watch short clips on YouTube but also watch 3-hour films and binge watch entire drama series on Netflix. I don’t see much evidence that consuming fluff significantly impacts our ability to consume material with depth. With the exception that they are competing for time.
You didn't provide any evidence for your claim either: "The problem is that when you go long periods without reading novels, it’s harder to pick up a novel and enjoy it. " Also, even if correct, you didn't address the risk factors involved that may cause "go long periods without reading novels". It's intuitively attractive (but I'm not going to research the research right now) to presume that "junk" content -- stuff…
But you’re right that I didn’t present evidence. I don’t think this subject has been meaningfully studied. So what I presented was an argument for why concentrating on “sporadic reading” is missing the forest for the trees. People used to say that TV resulted in a decline in reading. Now they say that reading crap results in a decline in ability to read books. If you want to be good at reading books, then read books and stop worrying about the other stuff. Reading crap on Twitter might make you a worse book reader, or a worse runner, or a worse painter, or a worse whatever. Practicing the skill you supposedly care about will do a lot more than giving up Twitter, regardless.
> It's intuitively attractive...
Intuition is the road to junk science. Don’t rely on intuition if you cannot support it with data or logic.