Seems to have only picked up in the last decade or so. Before that it wasn't really practical, and everything seemed to work fine without it.
When I was a kid, computers weren't connected to the internet. The first time I had a connection it was at 33.6 kbit/s (at 25 cents per minute).
Can you imagine if I had had all these 'modern' programs on my computer that would suddenly try to talk over that tiny straw of a connection? It'd be unusable!
There are still a lot of reasons why you would like to maybe hope that a computer doesn't try to randomly talk to everyone and everything on the intertubes on a whim.
For instance: said computer might be acting as a firewall, or it's being used for SCADA, needs to comply with corporate or government security policy, or is otherwise supposed to be something-gapped.
I guess for regular consumer technology that hope has long fled. You'd think that floss software could automatically be trusted to be quiet-by-default, but I guess that time is now past as well.
Possibly software that is quiet-by-default needs to start explicitly noting that it is so; so that if you have a particular task that really needs a quiet-by-default machine, you can draw from that subset.
You are right that audacity probably doesn't need to be in the quiet-by-default category. But ...eh... somehow this feels like a retreat.