At the end of the day, whatever the source file looks like, you’re turning it into an analog signal in order to make the speakers move. So how is it at all effective?
You can even send a digital stream of the bits over Bluetooth to speakers. So it seems like the ability to decode it is a fundamental requirement for it to be a useful file. So why even bother? It seems like it would be trivial to copy into a different format.
I think streaming services have become the DRM for music nowadays, though there are certainly ways around it.
They built what people back then told them wanted all along: if you give us music with a cheap subscription we won’t bother pirating.
What that did to artists and music quality is another matter altogether.
But yes, DRM achieves nothing.