Re: This is an application!
"what substantial applications can be written just by dragging stuff about and connecting things together?"
Well, here are a few examples that I've been familiar with in the llast few decades:
Example class 1: Lots of substantial industrial automation stuff can be, and often has been, done that way for decades. E.g. back in the mid 1980s when part of what is now being marketed as Industrie 4.0 had names like FunctionChart and FunctionPlan, or local equivalent, e.g. Grafcet. Underlying these things was often a concept called Petri nets, which have apparently become trendy again in the last few years in connection with the application area known as "graph databases".
Example class 2: National Instruments Labview and friends. Is "LabView as a Service" a thing yet? Somehow I doubt it ever will be, but I'm sure people will try to hype it up.
Example class 3: various design, simulation, and test (and other) applications in the field of electronic CAD (and similar related fields).
There are probably more. If you've never heard of these things, that's OK.
Also note that in a way, many of these things are a GUI layer and a set of less-visible tools, and a run-time system - but then, at that level of detail. maybe the pointy clicky web design things from the last decade or more fit that description too.
Anti-example class 1, from 1983: "The Last One", the program that writes programs, was supposed to be "the last programme you'll ever buy". Widely covered in advertorial in e.g. PC Magazine at the time (Google Books seems to find some classics) . Not so widely remembered.
Don't, don't don't believe the hype.
"editing wikis and designing photo-hosting websites"
That's a big part of the problem. The world of "IT" has become dominated by "presentation layer people", from the 'embedded' world to the high volume transactional world, and in lots of places in between.
To these folks, the concepts of concurrency and scalability, robustness, and maybe even security, are largely foreign concepts. E.g. Visio probably is closer to web design than real circuit design and simulation, even though Visio can in theory be used for part of e.g. the network design process.