This is reductive. It's true that interest conquers inattention, but the attention span crisis really represents a prioritization of exploitation over exploration. That is to say that many people are far less able to seek value in things which require more effort in the finding (e.g., long-form media such as books and movies). You could reasonably argue that this is not a real problem, but it is undeniably happening.
It can be both. I went through a very similar experience with school -- it was miserably boring to me, and I found solace in valuable and educational experiences I sought out myself at home. In this way I empathize strongly and I agree that the schooling system is massively flawed in this regard.
Still, from my just-as-anecdotal observations, it seems to me that social media addiction exacerbates the issues. I and many peers of mine fell out of reading for fun around the beginning of high school, and this was due in part to both technology and burnout from school. Screen addiction can be an obstruction to activities that one actually loves doing, just as school can.
This is just not true. My daughter, who finds school boring to the point of depression, has no problem spending hours reading the complete Akira manga in a foreign language. The crisis you are talking about is not in the people, but in the system.