Node-RED is a completely nifty piece of software and I hate it. Mostly because it doesn't do things how I like to interact with them (Not a visual programming person). Also it gives me flashbacks to dealing with Labview.
Don't think about it as visual programming because that's both inaccurate and will only mislead you more. Reason about it as a rule system for messages. You're designing little conveyer belts (or pipes if you prefer) for packets.
I haven’t used node red, but primarily program PLCs in function block or ladder logic.
If your problem can be well represented by a block diagram or transfer function then it probably lends itself to function block programming. The visual animation of the logic is very helpful to me in understanding the influence of different components on the final result and troubleshooting misoperating machines.
Briefly came in contact with it some time ago when our team had to hack up some demo for the IBM voice assistant. We disliked it very much, I have a hard time understanding what people see in it. Everything is cumbersome and slow.
You're simply not the target audience. It's brilliant for those that need what it does. I'm a developer, but when I need something quick and easy, I pull it out and it's great.