When I was in middle school, social media might have been omnipresent but even the really popular kids never exceeded 1,000 followers. In high school you could increase the upper limit on followers, but most people hovered around 250 to low 1,000s depending on their popularity. And I never heard anyone talk about their follower quantity, let alone insult people over it. I suppose this is my “kids these days” moment.
Then again, we all just had personal accounts for our friends to follow and weren’t trying to be some big influencer or social media star—maybe that’s what these kids are trying to do? Either way, I am really hoping what you overheard was just banter or an ironic joke between the two, and not legit bullying.