If you’re not working on a greenfield project, rather converting an existing one to Flow, that is absolutely a great reason to use Flow over TypeScript. Getting type coverage up as quickly as possible is really important for the peace of mind using a type system provides.
Writing TypeScript functions I’ve noticed this same problem of the compiler not inferring the type of a function’s arguments based on it’s return type and so I’ve gotten used to just annotating a function’s arguments every time, but the less you as a developer need to think about these things the better!
The tooling for Flow has definitely gotten better too, I’m using its plugin for VS Code on Windows for an React animation library and it works just as well as when I’m writing TypeScript.
I’ve also been running into issues with using the latest version of TypeScript and Webpack, modules are disappearing in my bundles, so the temptation of migrating all the projects I’m maintaining to Flow keeps on growing.