Definitely borrow from the library. If I bought every book I read, I would have been thousands of dollars in debt by now.

Definitely noticed this too. I think maybe it's because pulling out your phone and scrolling on social media is so low-effort and mindless, whereas pulling out a book and reading may be considered more offensive because it's so much more noticeable. Maybe reading just gives off a more discernible vibe of "don't care, not interested".