The specific issue with OSS was that it was never part of Linux and then with OSS 4 they made it proprietary, which killed it off entirely as far as Linux users are concerned. (FreeBSD cloned it instead.)
No joke, if you remove the new thing stuff magically starts working again.
... except when you have accidentally ended up with half-pipewire, half-pulseaudio setup due to half-forgotten instructions that were no longer applicable.
I have to say, that pipewire under NixOS had been easier to deal with than both pulseaudio and ALSA on crappy internal sound devices (i.e. ones requiring dmix and the like). It's nearly as plug&play as ALSA on "proper" soundcard was (like when I got a Dell Precision to work with that somehow had a Creative Audigy with 256 channel sound, so no need for dmix at all...)
Huh?
But alsa was/is also enormously complicated with a huge library, user mode plugins and whatnot. It reminds me of a common problem that people have where they think API and implementation are one and the same, and that you cannot swap out a different implementation keeping the simple API. People would say you need alsa because it does software mixing, but the lack of software mixing wasn't an OSS API problem, it was a problem with how it was implemented.
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)