You're essentially dealing with connected one-directional graphs of arbitrary complexity. Feedback loops are required for the eurorack experience. That's pretty easy to lay out visually, but I haven't seen good ways of laying it out in code. There's room for innovation here; Someone in the programming world has a more intuitive, more informative way of visualizing data in a graph that could be adapted into DAW paradigms.
But also part of the whole thing with modular synthesizers is you use whatever modules you want. As few as you want, or as many as your CPU can handle (or more if you're willing to ditch realtime).
So you would need a UI paradigm that can work for 2 modules with a couple inputs and outputs each, but also with a massive rack of hundreds of modules with up to dozen of inputs and outputs each. Do I want my fifth VCO to plug into input 3 of my fourth VCA? I'd rather just follow a cable visually.
Some synths do have a great UI that works for them. Razor and the original Massive are still among my favorite UI's for usability. But they're also more limited in their scope. (Yeah Massive is a really complex synth and could be your only synth for life, but true modular emulation style synths have an infinitely higher ceiling of possibilities).
That said, in general, what you see in software is a lot different. Mentioned elsewhere in this thread is Ableton Live (that has been around for many years) and is a DAW with a very clear design language that is all about the workflow and quite far from any real world device. But that's not to say that either approach is right/wrong - they both work.
The one drawback I find to replicating hardware, as VCV Rack does, versus something originating in the digital realm, is that more complex modules bring over their hardware-based UI compromises.
An example of this is the Plaits module from Mutable Instruments, called "Macro Oscillator 2" in VCV Rack. The hardware Plaits module is very compact, and uses a series of LEDs with little icons next to them to denote which DSP algorithm it's running. The only way to know what anything does is to look up that icon in the manual and read what each of the knobs do in that mode.
In a software-first paradigm, the UI would use a software UI pattern rather than a hardware one, most likely a drop-down menu instead of a row of icons, and the labels on the knobs would change based on the mode (this is actually how a port I'm working on of Plaits to the Reason environment is designed).
All that said, many modules in VCV Rack are quite simple and would be no different if they originated in software. Things like basic oscillators, envelope generators, and filters need no manual diving if you understand the fundamentals.
What is "this" for you?
For me it is a cheap intro/evaluation tool for the very expensive Eurorack hobby. To meet that goal it must be skeuomorphic. I can mess around with VCV + maybe a cheap (relatively) midi control to get some physicality. To discover my interest is superficial and lasts only a few months. Saving me from thousands of dollars of more "toys" that just sit on shelf.
But I guess by "this" I mean "making the sounds I want to make". If I'm interested in composing modular software components into a synth without regard to its physical analog, a wider range of designs is available for how "composition" or even "component" are reified. But the patch-cables-between-2d-boxes paradigm still seems dominant in that domain too, from my casual browsing of it.
Some examples: Bitwig's Grid (https://www.bitwig.com/the-grid/) and Patcher in FL Studio (https://www.image-line.com/fl-studio-learning/fl-studio-onli...). Afaik there is no equivalent in Ableton which I really miss sometimes (unless you consider Max4Live which is on a different level of usability).
I like the panel/patching split in reaktor, but it‘s an extra abstraction. They added "front panel patching" after all, so it must be more appealing to some people.. Audulus with it‘s parameters+patching on one level but no skeumorphism is at the other side of the spectrum.
To simplify this interface you have to relax the assumption that you will create a graph with arbitrary feedback loops: then your signal path can be acyclic or linear. Most things you will want to do in sound design use feedback in a very limited sense(e.g. a delay line effect) and can be turned into black boxes for a linear chain. Linear by itself is slightly too little power since you do want to mix and split signals at various points, and most commercial synthesizers use a "semi-modular" design that assumes a linear default and then adds particular methods of choosing modulation input at various points.
Regardless, modular's power to do anything is tempting to dive into. It's just a case of "not worth the effort" most of the time since having any input anywhere creates multitudes of obscure ways to get no output.
Right now I'm polishing a hybrid system, with hardware Eurorack coming into Bespoke through multichannel audio.