PipeWire: The Linux audio/video bus

> Quite the contrary. People had actual proper soundcards (me: ad1816 or cs46xx on daughterboards),

Just because you had high-end audio gear (for the time) doesn't mean most folks did. Even before Intel standardized onboard audio with the bog-simple single-stream AC97 spec, the overwhelming majority of the audio chips on the market only supported a single hardware PCM stream. Multi-stream hardware was always the upper echelon of the market.

> there was ALSA's dmix that would do software mixing via shared memory

I recall having a lot of issues with dmix in its early days. Not surprising as the same sorts of driver/library/application bugs that made PA a bit rocky also affected dmix.