Weeell "bullshit" is easy to claim but not necessarily untrue. So with android phones this is definitely a problem. Industry wide firmware support for these ARM SOC-s are often ranging from not long enough, to fucking atrocious. You get basically two years of new drivers, and a security update maybe. The way LinageOS manages to support phones like the note 3, from like android 4, to 11, is basically creating manifests, that use drivers from newer, still supported, but "similar-ish" components. And the note 3 was a flagship device, easily the fastest phone of it's generation. These Chromebooks, especially the ones schools can and do afford, are built to the penny. There is ultimately no point in pushing a software update to a device for a significant cost, that makes it so slow that no reasonable person would ever consider using it.
What is the solution to this? Hard to say. Not buying hardware so incredibly obsolete that it has to run an alternate OS, is a start. Maybe just use PC-s and deploy linux.
Basically competent support for hardware for laptops newer than 2014. Proper thunderbolt, displaylink, trackpad, fingerprint reader, facial rec support.