Certain classic computers powered by “AA” batteries are amazing to use today. I have an Alphasmart Dana set up for my children to play chess, do word procession, and learn to program in C. It is much better than dealing with the potential hazards of a modern device.
Basically, getting rid of dopamine-driven entertainment has been the key. Going back to the 90s with pocket versions of games like Oregon Trail and Where in the World is Carmen San Diego has been helpful. Board games, card games, lots of books, antenna TV, and DVDs for entertainment has made a big difference!