Yeah, I have this question myself a lot.
I thought I could just buy my kid an old C64 or ZXSpectrum, but those computers are just sooo slow and cumbersome now. They have the right spirit, but too nonstandard and weird in some ways. If you just want an environment to go over basic programming and doing sprite stuff, they can work.
One possibility is to get a raspberry pi kit that comes with a display and keyboard to where it is kinda like the old C64 experience. Depending on their age, make it a family activity. I doubt my kid would just go read on their own (at least now), but when I say it's reading time and sit down with them, it is usually an enjoyable activity. Start with Scratch and then later move to a Basic interpreter or Python. Programming is hard, but if they have little example text games to program and tweak, they'll pick it up little by little. To really learn, they'll have to keep at it (a few hours a week). It probably won't be super enjoyable at first, but eventually I bet they'll be happy once they can actually do stuff.
As far as Basic goes...Once you've taught them some basics (print statements, if-then, for loops, while loops, arrays), you can help them with creating easy games like tic-tac-toe, guess the number, a 3 room text adventure...etc. This will never be the dopamine hit that watching TV, social media, or playing Fortnite will be though unless they're really just into it.