[verri]

Indeed, imposing DRM is the whole idea :) https://en.wikipedia.org/wiki/Digital_Radio_Mondiale

But there are some benefits which you didn't mention, such as including text & images in the broadcast for people without internet access, kind of like what Microsoft attempted a decade ago with FM subcarriers. There isn't that much bandwidth available for analogue AM radio either; using DRM would at least double that. And then there's the claim that switching to DAB allows for decreasing the output power, but I don't know if that really holds true in practice.