My kids use Gcompris and a lot of the KDE educational suite. Unfortunately, I do not use KDE, so I have to maintain two separate desktop environments between their machines, mine and my wife's desktops, and every other machine in the environment.
There is a tremendous amount of educational software out there, which would be a major attractor for home-schoolers and educational institutions, alike. I am not sure how much is actually in the repositories, but I could take a look.
Here is a good site where one might start:https://schoolforge.net/