You probably did but, there are two Nvidia entries. I’m assuming you downloaded the one under Modern GPUs because it makes sense for your main PC, but a GTX 970 would need the entry that is under Older/Legacy GPUs.

Correct, but that is why there are two different Nvidia images, bazzite-nvidia and bazzite-nvidia-open. OP just needs to use bazzite-nvidia for the older/legacy cards.

If I were to speculate, they are waiting for the NVK (Open source NVIDIA driver) to be more mature. So, they wouldn’t have to release two versions and wouldn’t depend on NVIDIA to update their driver to work with software the Steam Deck uses. I.E. Steam Deck uses gamescope for everything outside of Desktop mode. NVIDIA’s driver didn’t work with it until 2 months after the Steam Deck release. Even though it had existed for years prior.

Since drivers are so specifc, people’s anecdotal experiences with having to install them is never going to be shared.

IE, I had to install a wired NIC driver just last month on a fresh Windows 10 22H2 for a Dell laptop that was no more than a few years old.