This is such an interesting topic @MSJ - thanks for starting the debate!
I think that originally radio stations were processed so heavily so that those listening in noisy environments could hear everything. It was radio designed for busy cafes, gyms, in the car with a loud engine and loud workplaces.
The temptation to hard limit by audio producers is even greater causing a double compression when something goes out on air.
I was able to learn the hard way by producing what I thought were great pieces and heavy compression. When they went through the Optimod they sounded like trash!
Now I think we’re getting to a time when compression and limiting can be dialled back a little bit especially for podcast production. I think your last point on considering the digital world is important. We no longer need to create the loudest thing on the FM dial to stand out. In fact creating the loudest podcast can work against you and hurt the heads of your listeners.