The more narrow the domain, the easier it gets to figure out a low-/no-code environment that will work for the users. But the smaller the base of purchases. And distilling the complexity to just the right level still takes some really bright domain experts with extremely good intuition of where the most profitable use cases lay (the hardest role to fill) and highly empathetic coders (also hard to fill) who work well together (extremely rare), or a single person who embodies both (unicorn).
If energy and money were no object, low-/no-code is absolutely A Thing. I believe there is some kind of emergent Shannon–Hartley theorem behavior here, where complexity down a communications network with certain noise/bandwidth/etc. properties has some suspected hard physics-as-we-know-it limits.
So it might be that node based programming is a good way to allow non-devs to interact with parts of an otherwise code based solution, inside niches. Examples that come to mind are eCommerce shopping rules. They can be complex, and really arbitrary, and in many ways having a developer implement them is really inefficient. Giving a node based pipeline editor for shopping cart rules would be a boon for power-users and take time off the dev's hands to focus on implementing the surrounding ecommerce solution, something you definitely don't want to be writing in a graphical editor.