How come you question the need for M2+ chips in iPads in one post but then state your hope for an M2 chip in the iPad Mini in your next post? Are you doing anything on the Mini to utilize the potential power offered?
In response to your question, for Macs people do real world stress tests using exports, renders, and file transfers in programs like Final Cut, Blender, and Lightroom. Similar (or same) apps exist on iPad, so I assume people are using them and benefit from the faster speeds.
But the Mini has a significantly smaller screen so I don’t know how useful those types of apps are on it, not to mention the significantly smaller thermal capacity of the Mini.