The point is all these things should be options, not single points of failure. We should be able to pay by coin/tap, or app when at a place we frequent. Apps should use a single system per region, props for being an open standard.
I don't think anyone is arguing that. While I wouldn't be surprised if app-only parking situations exist, I have never encountered one. Every place I've needed to park that had an app also offered the ability to pay with card (and often cash) at a meter or machine.
I saw it once and was so disgusted I haven’t been back to the location, for years. Have heard they went back to the old system but my habits have changed permanently it seems.
We have the technology.