The reason for this is because NVIDIA's Turing and above GPUs use a new microcontroller called the GSP, which is RISC-V based. From my understanding, NVIDIA has

The reason for this is because NVIDIA's Turing and above GPUs use a new microcontroller called the GSP, which is RISC-V based. From my understanding, NVIDIA has offloaded their proprietary IP from the closed-source driver to the GSP firmware (and not the older microcontroller present on Pascal and lower). This is why `gsp.bin` exists in `linux-firmware` now, and the FOSS driver targets the GSP (because now the proprietary stuff isn't in the kernel driver but rather a RISC-V ELF binary that runs on the GPU), not the older controller.