I think the main issue with most general purpose visual programming languages is, that they are still languages. So they are modeled in a way that resembles a text representation and can often be mapped to a sequence of symbols (a language). However, there are far less tools if you leave the explicit text representation (things like compatible editors, version control, etc.) so it comes down to being an over-the-top syntax highlighting at the expense of the before mentioned other tools. So, I think that visual programming would only become a viable alternative if it were to let go of the ideas of textual programming (language based) and become fully graph based.

If it's general purpose, then I agree that visual languages always seem to be an annoyance. If it's domain-specific, that's another story, since many domains are all about connecting blocks together. The most common use case is audio/video signal processing, where it works well if you're working above a certain level of abstraction.

Indeed, I've had mostly positive experiences with Isadora in the audio/video signal processing visual scripting space.

The 'Vop' (Vex OPerator) context in SideFX Houdini is the best 'node-based' graphical programming environment that I know of - however you're always working at something like a 'shader'-level. It's strength is in automatic use of SIMD and built-in parallelism (would not be a good choice to write an app in though!)

The node/noodle system in Blender is really good.

There's a node system in Blender?

Yep, shader nodes

https://docs.blender.org/manual/en/latest/render/shader_node...

Yes. The official node system can be used to script materials/shaders, image compositing, and there are a few excellent plugins to make it stretch to procedural modelling.

You can use it to procedurally generate textures in Blender

Houdini/Nuke nodes and vex. It's for a very specific application (computer graphics), but it's incredibly powerful and works amazingly well.

Bolt in Unity is _very_ nice. Seriously. Not "code grade" kinds of nice, but plenty good enough for map logic.

Yeah redstone in Minecraft is pretty good. Very visual. Few people have made entire CPUs

https://youtu.be/ydd6l3iYOZE

It is still just connecting blocks though as pierrec says below so it can take a lot of connections to get something done