Prior to that people would at least need to sit down and dedicate attention to whatever they were doing online at their desktop.

It required at least some technical base knowledge.

While nowadays pretty much everybody can, and will, pull out their smartphone even during very short breaks: It' all short attention span, relegated to devices were multi-tasking is way more of an hassle, which means people are also way less likely to do research on whatever they are discussing.

It's gotten to a point where in many places writing anything longer than Tweet length is considered something bad, as most peoples attention span just can't cope with long-form forum posts anymore.