I had adhd long before cell phones or social media. I don't think that's driving the diagnosis of it, I think more people having access to healthcare and knowing how to advocate for themselves THANKS to social media may be contributing to increased diagnosises though.
The "increase" in neurdivergent cases probably might also have just a wee bit to do with the fact that punishing your kids until they learned how to pretend to be "normal" isn't as popular as it used to be.