Driving and walking are wildly disparate modes of transportation, and having them coexist in adjacent physical space and intersect each other inevitably requires some set of rules describing who will have priority and when.

Many intersections in cities simply have a fixed repetitive cycle of granting priority to different modes in different directions each in turn automatically. Those which require explicit "requesting" of priority typically occur when traffic of a given mode or in a given direction is light enough, compared to other modes/directions, that the overall highest throughput occurs from explicit request. It's also not incredibly burdensome to use a button for this in the case of the pedestrian; detection mechanisms for motorized vehicles/bicycles on the road are there because a button would be unwieldy for those vehicles, not because designers of intersections want to force pedestrians into some type of ultra-lowest-class group. Indeed, the "high class" (in your view) automatic detection is often unreliable and leads to a far more conscious feeling of having to work to obtain priority, as vehicles shift forward and back hunting for the magic spot that will trigger the detector.

And honestly, the number of buttons which are non-functional but simply exist to provide a placebo feeling of speeding up an otherwise fixed pattern in which everyone gets priority in turn makes it kind of a silly argument anyway.