I think this is because the approach isn't that different the mentality was. Encoder only classification isn't new. General encoder only classification isn't new. Gliner2 was something similar for parsing. But what they did is provide a new way to look at a sub-class of problems. They opened a lot of people's eyes, including my own, to the demand for applications in this subsection of the market.

But once you have the mental shift, everything else has been done before. So it's not super hard to build something similar for your own use case.