ALSA started replacing OSS on linux before software mixing became as critical as it ended up, because people still often had proper sound cards with multiple ch

ALSA started replacing OSS on linux before software mixing became as critical as it ended up, because people still often had proper sound cards with multiple channel hw mixers. The assumption that you could punt software mixing to hardware or deal with limitation of only one program accessing the audio at a time took a hard hit when Intel HDA pretty much decimated presence of such hardware on PCs (AC'97 was much less pervasive for various reasons)