There are much deeper and more sophisticated reasons why inaccessibility to screen readers is not really the core of why we should consider audio production software to be inaccessible.
This is a debate/discussion I've been having for 20+ years now (as the original author of Ardour).
The GUI of a typical DAW (or even a moderately sophisticated plugin) serves as memory aide for sighted users. 48 tracks? Which ones did I mute? A sighted user doesn't have to remember - they can just look.
Sight-impaired/blind users of older hardware mixing consoles use the tactile experience of those devices to partially fulfill the same role, which is why modern full digital consoles with tap-only-LED-lit buttons are so much harder for them to use: they have to either remember or investigate which features are enabled and which are not.
In addition, most DAW and many plugin GUIs present information in ways that are more or less inconceivable for screen reader presentation. Waveforms are the obvious example, although here perhaps sight-impaired users have what some would consider an advantage, in that they are forced to work entirely by ear, rather than use on-screen representations that have only a debatable relationship with the sound.
But routing presents another area where it can be very difficult to present the current state in a way that could ever be rendered meaningful by a screen reader.
Please don't think that I don't view accessibility or i18n as of critical importance - I absolutely do. But I also think that when application niches (like audio production) evolve their own highly-developed visual language to supplement and assist (sighted) users, that the correct/better answer for sight-impaired users may be non-graphical applications rather than trying to figure out to how speech-render the graphical representation.
This is one area in which Linux is far ahead of Windows and macOS: there are numerous command line applications available for audio production which would strike utter fear into the hearts of most sighted users, but that turn out to be incredibly great for sight-impaired users. Ecasound, I'm looking at you (among others).