Another speculation: Even if *if* there currently are no ways aid organisations that help organisations are using the building shape and size, it is not unimaginable that they would want to do that in the future. And while enhancements to OpenStreetMap normally are progressive, meaning you add information (building height, function, material) to existing objects, going from nodes to outlines requires re-drawing every building. So if we would be quick now by drawing buildings just as nodes, then in a possible situation where there is demand for building outlines, we would have to start all over again.

Another speculation: Even if there currently are no ways that help organisations are using the building shape and size, it is not unimaginable that they would want to do that in the future. And while enhancements to OpenStreetMap normally are progressive, meaning you add information (building height, function, material) to existing objects, going from nodes to outlines requires re-drawing every building. So if we would be quick now by drawing buildings just as nodes, then in a possible situation where there is demand for building outlines, we would have to start all over again.