Yes, I think this is about right. I see a lot of threads focusing on APIs and ignoring another thing that happened right around the late 1990s to early 2000s: M

Yes, I think this is about right. I see a lot of threads focusing on APIs and ignoring another thing that happened right around the late 1990s to early 2000s: MMX introduced SIMD to the PC platform. Suddenly real-time DSP algorithms were feasible for playback and synthesis on the host CPU instead of requiring a peripheral with an embedded coprocessor. This allowed soundcards to be refactored as "just" hardware IO channels, with other signal processing effects happening in the application. At roughly the same time, there were more peripheral buses like USB and Firewire being introduced, which meant that an add-on peripheral did not need to be an internal ISA/PCI card in order to have sufficient bandwidth for rich audio streams. These external devices could also be built with lower noise/interference compared to the boards inside a computer. And of course, silicon integration always increased so that the bundled onboard IO chip became good enough for many users. So, add-on peripherals had to move up market or into niche settings. That is a bit like how the iGPU in Intel CPUs got rid of the market for basic VGA/XGA/etc. graphics cards for office machines.