Pulseaudio is NOT a failure lol
ALSA, Esound, OSS etc were always conflicting pre-pulseaudio. Sometimes you'd get sound, you'd always have to screw around with the sound server settings in different apps between KDE and Gnome apps, and gaming was a disaster. Even just using XMMS2 was a pain with Netscape/Firefox
It was a huge step forward, even with initial teething problems.
The only thing it didn't solve was low latency (for music production), and that's really the huge advantage of Pipewire. It did take a while to get there though..
In Xfree86 days, Linux wouldn't have had a future if PulseAudio wasn't released. It was one of those critical elements (along with Compiz, XrandR, DRI, Udev, PackageKit and Steam) which actually made Linux competitive against OSX and Windows at the time