You got me there. I guess I think of specific trades that don't have those aspects. As far as I am aware, you don't need a state license to be a machinist. But yes, you do need those things to be an electrician etc.

So I guess software development is just basically like bagging groceries. Totally informal.

See now I don’t think I’d consider grocery bagging a trade because there isn’t really any skill involved. You could pick just about any person off the street and they’d be able to bag groceries.