Which models have you given them? Linux has been my computing best friend for more than a decade and I have also enjoyed using the Raspberry Pi 400.
But the Raspberry Pi 500 (keyboard model) is even better and (literally and figuratively) a cool design. You get 8GB RAM, boot from NVME, Debian with Wayland (labwc), and the R.Pi community.
They both use Raspberry Pi 500s. Seriously the support requests are zero. They both know that if anything weird happens, they can just pull the USB cable out of the back and plug it back in and everything will go back to normal. They seriously mostly use web browsers and my grandmother absolutely loves her gigantic monitor.
But the Raspberry Pi 500 (keyboard model) is even better and (literally and figuratively) a cool design. You get 8GB RAM, boot from NVME, Debian with Wayland (labwc), and the R.Pi community.