The Linux community is already past the problems of proprietary drivers. We are talking about people that reverse engineered a full network stack, graphic cards, audio devices, you name it.
This statement is horribly wrong. The sad state of even wireless ac drivers in Linux today show that there is a severe lack of driver development. What makes you think that a more proprietary and more guarded cellular modem will have better driver support than the current state of driver support? Isn't this just wishful thinking?
This is true for a subset of desktop/laptop/server hardware, but is nowhere near correct for other Linux devices like smartphones, routers, or SBCs.
And for the most part the mature Linux Desktop/Server ecosystem isnt full of reversed engineered drivers, its full of open source drivers contributed by manufacturers. My Linux Laptop works well without binary drivers (a firmware blob or two excepted) because Intel spends the time and money to employ people to write drivers for their GPUs, WiFi, etc.