Pipewire for some reason insists on using GTK4 for its UI though, which hangs X cold if you use any of the popovers in it. I didn't even know it was possible to hang X like that.
EDIT: Perhaps the parent means Helvum, which ldd says links to libgtk-4.so.1 => /usr/lib/libgtk-4.so.1. However, I can't figure out how to open a popover (https://python-gtk-3-tutorial.readthedocs.io/en/latest/popov...) in the app; all I can do is drag to create or break connections.
I haven't tested EasyEffects. With that in mind, PipeWire is buggy AF for the time being, and I've been working over the past week to clean things up (fixed a few bugs in plasmashell and pipewire so far, but I'm still learning and there's a great deal of bugs I haven't diagnosed and explained to the maintainers, it will probably take weeks longer for me to work through everything, and I'd very much prefer the program was written to handle race conditions and edge cases properly, instead of leaving users to discover bugs and trace the root cause through the labyrinthine IPC-heavy event-driven codebase after the fact).
An advantage of C is that it comes with a stable ABI, where Rust is unstable and C++ is a subject of conflict (though you can achieve a stable ABI by restricting your external API to C functions, and if you want cross-shared-object virtual calls like Pipewire, you might have to write the same pile of macros as PipeWire, which you were trying to save yourself from). The downsides are memory and type unsafety (surprisingly the only crash I've seen so far is a null pointer dereference, and I haven't hit any obvious memory or type errors), and a complete absence of "vocabulary" or templated types (they've created their own slotmap-like ID allocator but without a generation count resulting in ever-present "logical use-after-frees" in library and application code, and an intrusive linked list which they use even when hashmaps might provide somewhat faster iteration and asymptotically faster search).
The saving grace is that it can at any time be switched over to be built with a C++ compiler, and then start to be modernized incrementally.
It would be cool (not necessarily useful, probably not a good use of time) to rewrite it in Rust while keeping the dependency count in the single digits. It would be helpful to contributors to add architectural documentation.