What is this "CBSE Vaanam" thing?

I’ve been noticing a lot of chatter about this thing called "CBSE Vaanam" lately. As someone who went through the CBSE system (finished school in 2008), I initially brushed it off as random comments online. But then, I saw it pop up in roast videos of movies, where someone mentioned a lead character being a "CBSE Vaanam" and even writing an apology letter because of it. What’s the deal here? Back in my schooling days, there wasn’t any of this "state board is bad" and CBSE is damn good narrative. These days, I see it all over Instagram and YouTube comments, and honestly, it’s a bit baffling. Is this some kind of inferiority complex at play? Like, is it just a way of saying the state board is "mass" and other boards are "screwed"? I’d love to hear others’ perspectives on this.