I have never heard of this approach. It does sound interesting in theory, but I have a hard time seeing this work beyond the simplest of CRUD apps.

My initial concerns would be:

- Maintainability: the "duct-tape logic", as you put it, sounds like spaghetti code from hell. Making sense of a feature comprised of tons of chained third party calls will be a nightmare.

- Expressiveness: complex functionality may require complex code. I don't quite understand how you would write even medium complexity algorithms using this system.

- Reliability and performance: you are now entirely at the mercy of third party providers. This is often the case with SaaS products, but this seems like a particularly severe case. Each hop reduces performance as well, which may impact user experience (assuming we're talking about user-facing features).

- Quality: by moving business logic out of code, you're throwing out testability, so no more unit tests. I guess integration tests could still happen, but they're going to be slow, expensive, and involve someone writing the actual code - which, given the premise of product managers creating features, seems very unlikely.

Code is data but now no data is code.

this only works for very early stage

Sounds quite similar to how running an internal dev shop in an enterprise environment used to be, before SaaS apps took over. "Power users" would write basic apps in SharePoint, Domino, Business Objects, or other such "low-code" platforms... even Salesforce in its early days. It worked fine for department-level CRUD/LOB apps. If anything they were doing grew and became important enough that their lack of engineering skills became a problem, us IT folks would come in, take over the app, refactor it, and make in an officially supported app. But we would have hundreds of half-baked apps out there that were good enough to handle the small stuff that small business groups needed. We focused on keeping the platforms up to date, running well, setting up various data they could query, etc.