I run Raspberry Pi zero devices headless and connect to them using VNC to get graphic output and mouse and keyboard input and SSH for command line only control.
I use RVNC on my Android phones to connect.
There are VNC clients for chromebooks.
VNC is not the easiest thing to initially grasp and set up (especially for non techies), but once done it is painless to use.
Seems like Raspberry Pi might be a potential solution in that you could create a "standard" setup for the raspberry Pi with a set of easy to follow instructions for how to set up VNC.
The Pi zero W is about the same cost as an Arduino ($10-$15) but is so much more capable, powerful, with much more room to grow.
And also offers the ability grow from an inexpensive headless configuration to a more full fledged standalone system with monitor, mouse, and keyboard.
Raspberry Pi can also offer lots of additional capabilities and learning options since runs a real os (linux) which includes lots of development tools.
i.e. languages, debuggers, scripting tools, source control tools,
not to mention video and sound capabilities even when using in headless configuration.
--- bill