The ones who get bit by the programming bug have their whole lives to be annoyed by the hassles of computer ownership, upgrades, etc.
But most won’t keep programming, so I think it’s smart to at least keep this class focused on its purpose, which isn’t to see who can get most frustrated by their decade old Dell tower.
Let’s say there are a dozen kids in the class. The library provided the monitors. How does the volunteer teacher get a dozen towers to and from the library? What do they do with a dozen towers in between classes? Would this be easier or harder with a dozen Pi 400s?
This is the real strength of the Pi 400 for this application: sure you could do it all cheaper with used office hardware, but it turns this "just works" intro class into a full advanced IT course (or a full-time IT job for the volunteer teacher).
If you want the RPi look and feel &/| if you happen to have said PCs lying around &/| buying brand-new Pi's is not an option, you can get Raspberry Pi OS for x86.
But most won’t keep programming, so I think it’s smart to at least keep this class focused on its purpose, which isn’t to see who can get most frustrated by their decade old Dell tower.