I have a 14" System76 Gazelle running Debian with hybrid graphics through primus-vk-nvidia[0] and the proprietary drivers and I would say it works fairly well, albeit only after a substantial amount of trial-and-error with the configuration to make it stable. (Most notably, I blacklisted the bbswitch driver since it tended to cause lockups—the system seems to work just fine without it.) Most applications rely exclusively on the integrated Intel UHD Graphics 630 GPU but I can add a "pvkrun" prefix to any command to have it render on the discrete GTX 1660 Ti and copy the image data back to the iGPU for display. I haven't fully optimized the power consumption, but the driver for the NVIDIA card is unloaded when not in use so the discrete graphics should be completely idle.
I haven't used Pop!_OS much lately, but from what I remember at the time I received the system with Pop!_OS preinstalled there were options in the main menu (alongside shut down / reboot) to switch between integrated and discrete graphics. The change involved a system reboot, and there wasn't any support for hybrid graphics.
[0] https://packages.debian.org/sid/primus-vk-nvidia