Enabling video display without a `/proc/fb` device

Under Linux/Ubuntu: I had an impression that to have video output (either in console mode or GUI mode), there must be a fbdev listed in /proc/fb. But today on my system, I installed a NVIDIA GTX1650 card, and under /etc/modprobe.d, the options nvidia-drm modeset=1 and options nvidia-drm fbdev=1 are disabled. After reboot, the system shows that /proc/fb is empty, but the X11/Gnome desktop is showing up correctly. I guess I must have a mis-understanding of the implications of /proc/fb content. Can you please give me some hints on that?