When I was in 9th grade it was netbooks with Windows 7 and they were also terrible and fated for the recycling bin before I was a junior.
In most enterprise IT your lifespan for hardware is between 5 and 7 years maybe 10 for printers and network switches.
I'm sure most schools try to stretch hardware as far as it will go but IT would have known when they bought the Chromebooks that they'd not be long for this world as cheap as they were and that's the price they would pay for paying such a low price.
I think what is sticking up the works is on an administrative level, higher ups are expecting IT departments to stretch EOL dates like they used to do with Windows machines but now they absolutely can't and Admin didn't plan to have to buy all new whether or not IT did