My take on visual programming is it's easier to start out with, but you're quickly better off using a conventional language once you reach a certain scale or you need to manipulate your program in certain ways.

Almost every time I see an expression builder in a UI, I think it would be better off with SQL syntax and autocomplete because the dropdowns get old fast, and SQL expressions aren't that hard.

The problem with COBOL is that you can't afford "better", you can only afford "good". Excel should be a sufficient demonstration that visual programming is doable beyond the start.

Some SQL expressions can get extremely complex.

True, but imagine that in a query builder GUI.