Meanwhile, I can find no official tutorial from Google

This is such an unserious strawman of an argument, how do you not get embarrassed writing this?

There's no official tutorial for most Android devices either, it doesn't mean it's harder to do than on Apple devices.

Even if your premise weren't demonstrably untrue

Just saying something is so doesn't make it so, to demonstrate my premise is untrue you have to actually demonstrate how it's untrue, which you have not done.

it's about the kind of workflow the device would encourage for a typical student using it

You mean like how Mac OS is locked to the Mac OS App Store by default only, featuring mainly proprietary payware unless you toggle an obscure bypass in the settings, while ChromeOS lets you run any unsigned code for ChromeOS, Linux and Android with minimal effort, all of which are either fully or partially open source and comes with a web browser equipped with a nice set of easily accessible Dev tools, which allows you to examine and learn how web applications are written, architectured and deployed - the largest by far aspect of computer science and software development most people come into contact with regularly?

Even if the conversation was about what you say, you would still be wrong. But it's not about that, because in a school scenario both would be locked down with an MDM - in Apple's case literally via serial numbers and network connectivity DRM you can't realistically block.

And no, this conversation is actually not about that either. A user repairable device doesn't become less repairable if it discourages your 12 year old from popping out and eating the battery.

severely restricts your ability and incentives to meaningfully interact with your OS outside of a browser.

Any examples on this one, chief? Or you just saying things like that will magically make them true again?

Even assuming that the process of gaining root access mattered to this discussion (it categorically doesn't),

Of course it does. Really it's the thing that matters the most.

Sorry but your bailey castle isn't any more secure than your motte, because access to root is actual freedom over your device, anything less than actual unrestricted root access where I can say, replace the network stack or write and add my own kernel modules for hardware support I want to add or whatever reason I please is by definition not really software (and by extension hardware) I have control over. It's just another blackbox walled garden.

what you can and cannot do with that root access would matter far more, and in that unrelated discussion, macOS clearly still wins out

Again, do you have any evidence at all to back that up?

And what's with this weird caveat?

(unless you'd want to argue that developer mode lets you install Linux, at which point this is no longer about Chrome OS).

It's some real specious reasoning to handwave the most core freedom of all - to simply replace/refuse the OS altogether and bring your own to your hardware, and highly convenient of course because Apple employs many anti-repair, anti-consumer, anti-modification practices from the very screws to their knock-off TPM (T2?) chip to hardware whitelists where everything is married down to the cables and each and every module for no reason other than to maintain control above all.

Please apply more intellectual rigor next time.

Fuck Google and fuck Apple, stop defending them, don't die on this silly hill and go be free.