If you're wondering why the paper seems to complicate "simple" constructs by converting them to control flow graphs — that's because many other kinds of static

If you're wondering why the paper seems to complicate "simple" constructs by converting them to control flow graphs — that's because many other kinds of static analysis, like tracking when variables are initialized and overwritten, are even more puzzling when trying to analyze very stateful code directly based on the syntax tree. The graph representation allows splitting the code into smaller blocks, and remove a lot of statefulness from them.