For as long as I can recall, it seems that every couple of years someone decides the current state of audio on linux is terrible, but instead of trying to fix the existing available code, they start a new project. Usually there's a node to maintaining compatibility with other libraries, but that interoperability stops right where the new project thinks the old projects are Doing It Wrong.
The X vs Wayland fight is polite to a fault in comparison.
NSM can potentially be used with JACK on win and macos. It also works with JACK implementation of PipeWire for Linux.
I expect Linux audio to converge on PW (unifying alsa, jack, and pulse in the process).
Linux video has this split with Wayland which is a whole different problem (I want my fluxbox :/). PW originates as Pulse Video, and designed to work with gstreamer pipelines and wayland compositing. aiming for better userspace separation of hardware and applications. I really love the idea of having JACK, but then for video. (no more vloopback hacks, named pipes or random socket servers to bounce framebuffers between applications)
JACK will then live on for dedicated Pro Audio applications and hopefully on win and macos as the old-skool "this also works" audio API that really only a small niche uses (and can break at the snip of silicon valley's fingers).
The X vs Wayland fight is polite to a fault in comparison.