Earlier quoted context omitted.
The ideal Linux laptop is one with just Intel integrated, and no discrete GPU. Honestly, Intel GPUs are decent enough, even if you want to do some mild gaming. Handing two GPUs on a laptop in Linux doesn't have the best support. A lot of the Optimus/Bumblebee stuff is not very well maintained.
True, I don't do any laptop gaming. Intel GPU's seem to be sufficient as long as it can easily power a full HiDPI internal monitor + 4k external monitor... which Librem's Intel 620 GPU is listed as supporting but it looks like Librem's 15 v4 only has an HDMI port and not usb-c/displayport, which limits it to 4096x2160@30Hz instead of 4096x2304@60Hz. So I guess you'd have to look at Lenovo, HP etc for top tier.. Sadly…
IMO the ideal GPU for a UHD screen would be either an Iris or a Vega 10. But it's difficult to find the former outside MacBooks and the latter with more than an FHD screen.