My point was quite the other way around. With those legacy tools it is very simple and most people would just build the feature. Serverless adds more friction if you don’t have a suitable backend. And this makes sense then.

The point is that this crazy architecture could (perhaps) only be justified if all my backend is outsourced to external serverless points.

The moment that I need to have my own backend to manage some data, I can add the item rating data as well and your system becomes more complex than the built-in solution.