[phendrenad2]

A service layer is also a single point of failure. So if uptime is a concern, one less component that a developer can accidentally take out and bring down the whole system is valuable.

One of the most pernicious dangers in shipping a successful project is you paradoxically both cargo cult and critique random parts of your success. Looking back, you might decide that choice A was correct, while choice B was incorrect. But you don't have the benefit of having tried all of those other options. So don't trust postmortems too much, they are single data points in a sea of failures. They could very well be random chance.