Other creative toys/products that come to mind would be, say, Play-Doh as a sort of children’s intro to…Clay, I suppose? But in this vein without being exclusively directed towards children (albeit I imagine many may be).
Always enjoyed a creative kind of toy to mess around with.
I never had LEGO, but when I was a little kid, my parents got me several Meccano kits (not these ones tho) and this electronic experimental kit
and, 20 years later I mess with Arduinos and Raspberry Pis.