Mechanical toys can be “screwed with” a lot. Like experimenting with a ton of “what if…”
Electronic toys generally don’t give you much of this.
And I think this really represents a fundamental change in a lot of aspects of life: there’s a specific way to interact with things, prescribed by the maker.
I absolutely loved the quiet weekends as a kid where I could spend hours and hours making ridiculous contraptions by mixing toys and a bit of tape and such.