I think it's not so much as the vendors of the graphics card and such that only released closed blobs to go with the open drivers in the kernel. And while they may work with say, ChromeOS, getting them to work on Linux isn't as straightforward. Android has a similar issue, though most of the time people aren't jumping from Android to another OS..
I didn't realize ChromOS was in the same boat. That's really shit. In traditional Linux, a lot of drivers get merged right into the tree. Even for proprietary drivers/blobs, we have linux-firmware. For the most part, the initrd files on Arch/Debian/Ubuntu can load a lot of modern hardware.
I wish Google Android/Chrome devs would get their shit together and stop this individual build madness. An initrd full of drivers and linux-firmware do not take up that much space, and many phones now have the footprint of tiny laptops vs the old <8GB tiny flash roms.
Google wields a heavy hand with their (no-so-)open handset alliance (OHA). They can get manufactures to at least commit their blobs to a standard google-firmware package and keep a fork of their Kernel that builds all major drivers into a standard initrd package. Manufactures could always strip out all the crap for their custom ROMS, but this would allow AOSP to just run, out of the box, like Windows 10 or Ubuntu, on a large chunk of hardware.
Google's decisions in Android structure feel asinine.