I showed a bit of JS and while Scratch did get a bit of the way in explaining concepts, it's simply too inefficient to get anything "serious" done.
What stuck for my older kid (12 now but started with it at 11 or earlier) was Roblox (with it's Studio), he was already playing the game a lot and making levels was fun and to get them beyond the basics one needs to script and even if 3d maths really were above his head (I've explained 2d/3d vectors and angles) the connection to something "real" has really helped him push through most obstacles. He writes horrible code by copying kinda bad tutorials on Youtube but getting things done is fun enough that he just keeps going and lately helping him debug issues I've noticed that he's started to develop the intuition about reasoning about states and the effects code has on it in an async picture.
TL;DR Find the areas your kid might have passion in and if there's a way to mod/play with it with code the sheer fun will help them push through the drudge.
What stuck for my older kid (12 now but started with it at 11 or earlier) was Roblox (with it's Studio), he was already playing the game a lot and making levels was fun and to get them beyond the basics one needs to script and even if 3d maths really were above his head (I've explained 2d/3d vectors and angles) the connection to something "real" has really helped him push through most obstacles. He writes horrible code by copying kinda bad tutorials on Youtube but getting things done is fun enough that he just keeps going and lately helping him debug issues I've noticed that he's started to develop the intuition about reasoning about states and the effects code has on it in an async picture.
TL;DR Find the areas your kid might have passion in and if there's a way to mod/play with it with code the sheer fun will help them push through the drudge.