I think the best learning experience is seeing you can still build and repair a computer yourself, so I had my 8yr old kid build his own gaming PC from scratch (with me standing by for guidance). We were about $1200 in with parts: motherboard, cpu, ram, nvme, chassis, dvd-rom, etc.

Then he got to help as we installed dual-boot Ubuntu and Windows, with Ubuntu being default :)

In windows I installed some games I felt ok about. Microsoft Flight Simulator, Kerbal Space Program, Pokemon TCG, his school office apps. But I only let him run Minecraft on the Linux side, so he will have to boot there and sort it out from time to time, with the bonus of a Minecraft server environment we've hacked a bit.

We're no longer in the 80s, that's for sure! But I think focusing on learning the components of hardware/software in computing are better done on a desktop than a laptop or tablet. There's really nothing to be learned in today's repair-hostile walled gardens.