NVC0 Gallium3D is barely maintained these days especially compared to the actively-developed NVK driver within Mesa by Faith Ekstrand of Collabora and other open-source developers. Plus Zink has been showing its successes at large for working well across multiple hardware drivers, Imagination going the Vulkan-only route with their PowerVR driver to rely on Zink for OpenGL, and Mike Blumenkrantz of Valve really driving hard on Zink optimizations and fixes.
With this merge request in the process of being merged at the moment, Mesa 25.1 with Nouveau will load Zink as the OpenGL driver for Turing and newer and when on a supported kernel with DRM modifiers support. It's a logical move to make given the stagnation of the NVC0 driver. Most NVIDIA users will still be best off using the official NVIDIA Linux driver stack with proprietary OpenGL/Vulkan especially given the headaches with the current Nouveau kernel driver (though with time the NOVA kernel driver will hopefully take shape well and become a viable alternative) and now another win for Zink in the books.