Because they're doing this for fun. A lot of kids genuinely enjoy the process of making games.

Why spend money on expensive Legos when you can buy any imaginable plastic toy for cheaper on AliExpress?

I suspect even with AIs certain kinds of people will still enjoy creating by hand. Certain kinds of people won't, of course, and that's ok.

Why learning anything, if we have GPT-4? Why even commenting here, GPT-4 could do that, too ;).