Historically speaking, between average Android device and average Chromebook, latter is far easier to get mainline kernel + "normal" Linux distro running, e.g: 8 Chromebooks vs. only 1 Android device (and even that is a dev. board) in official Arch supported hardware list:

https://archlinuxarm.org/platforms

Alas, new Chromebooks are no more. "Successor" Googlebooks are all Android.

As is WebOS, Raspberry PI, Beagle Boards, netbooks, PS2Linux, PS3 OtherOS,....

Regular OEMs will never give their differentiation factor freely.

Even Linux OEMs like Tuxedo apparently cannot get access to hardware specifications, and have to reverse engineer their own devices.