[Blackthorn]

With connected cables, you can see at a glance what feeds into what. I can't imagine anyone being able to do the same with reaper's in/out pin matrix.

[bambax]

Here's a patch for "Complex-1", an attempt by Reason to do a modular synth: https://cdm.link/app/uploads/2018/12/cables.png

Given the nature of that synth, there may not be a better way to do this, but it's still far from clear what does what at a glance, or even after staring at it for a while.

[PaulDavisThe1st]

The old EMS hardware synths (and it bigger cousins) that used a pin matrix were often said to be much easier to grok than systems with cables.

[Blackthorn]

On that note there's a modern hardware synth that uses a pin matrix still -- Eaganmatrix (used in the Continuum and the Osmose).

IDK, some people say it's really hard to understand, but I think the pin matrix they use actually works really well.