Linux

The biggest roadblock will be whether the bootloader will allow another OS. You should be able to search xda forums for your device as a start.

Linux can be installed on ARM, no problem.

Does chromebook hardware need special distros? Debian has an armv7 port, there's Arch Linux ARM, Gentoo packages build for arm (though I feel like you'll have a horrible time building anything on that piece of junk), etc.

Though ARM is notoriously horribly inconsistent when it comes to bootup so I don't know if any of these will work on this specific device.

I know ArchLinuxArm (a fork of the ArchLinux project) supports the Hisense C11. It does seem to be a fairly involved procesd, and (potentially?) requires using external media rather than the onboard eMMC storage to boot a Linux system.

Your particular Chromebook contains the same SoC (Rockchip RK3288) as an Asus C201, which Debian has an install guide for. Once again, a fairly involved process and this one may not be guaranteed to work if the C11 has some quirks not present in the C201.

I think the real question is, what do you want to repurpose it for?

Because the answer to your question is yes, it is usable, but whether or not it's capable of what you want to use it for, we can't say without more information.

Linux installation appears to be possible. This is a wiki to an Arch on ARM distro, but you might want to look for something a bit more user friendly if you're not comfortable with Arch.

https://archlinuxarm.org/platforms/armv7/rockchip/hisense-chromebook-c11#installation

Just remember, it's a fairly low spec machine. Think of it like a Raspberry Pi with a keyboard and monitor built in, in terms of what you can hope to run on it.

I am using a couple of old chromebooks for LibreELEC and am pretty happy with that result

if nothing else, if you create a wifi network with a separate VLAN and no internet access, you could use it for Grocy in the kitchen, or for HomeAssistant/openHAB, as a remote controller for Jellyfin or Kodi, or something like that. basically as a touch screen for some internal service.

Strictly with no internet access, though. Make sure to verify it. Maybe also install an app, or write a script that periodically checks this and notifies you if this has changed, not too frequently though to not drain the battery significantly.
The Nock Nock app from F-droid may be good for this with the JavaScript evaluation mode and a simple condition

on the more technical side, for x86, chromebooks have a special UEFI firmware that only makes it possible to boot chromeos, and so the first step is to replace it with the firmware distributed by MrChromebox, which makes it work similarly to a regular laptop.

but, MrChromebox does not have firmware for ARM chromebooks, so replacing the OS may not be that "easy" in your case. if you don't find a way, it's best to treat it as an untrusted device, and follow what I have written in my other comment

There's nothing you can do with that one I think, for two reasons:

1. MrChromeBox's firmware doesn't support this model. That's the guy's site that tells you how to unlock the bootloader and install the new firmware on it, that allows you to then install another OS.
2. It only has 2 GB of RAM. For a better online experience with any modern Linux, you need a minimum of 4 GB. You could install though something like Kodi, or librelec, or some game emulation distro instead of a desktop OS. But without #1, you can't do that either. That's a landfill laptop AFAIC.

Looks like it is supported in Postmarket os. I just installed that on a Lenovo Duet arm based Chromebook.

Off the top of my head, GalliumOS or nix