It really was. In the early 2000s I had a stack of Mac laptops doing exactly this. Made some decent cash advertising locally to rip people's CD collections!
A good list. I would definitely recommend Blackhole for Mac. It is easy to recompile and create multiple virtual devices. With the OS Aggregate Device feature, you can do some good complex setups.
Another one for Windows is ASIO Link Pro, which is quite old but still works well under Windows 10.
