Our last vendor drop of PulseAudio was version 6.0, back in 2015. The latest release is 17.0, released in early 2024. There is also 16.2, released in late 2024. Not sure what's going on there. Having such an old version means that we are missing out on bug fixes, and possibly useful features. It's also in the way if we want to do further development. Bug 8591 was one case where we had to backport a fix instead.