Make changes from component to app.data vs emitter

We are developing a small module using vue and components. We want the components to be self contained. Is it considered bad practice to change data by calling app.data vs using emitters? If so, why/what issues can arise from using the app.data method?

Thanks in advance for your time and consideration.

CL

As for me, the main advantage of using emitters is the prevention of tight coupling between the components. Therefore, if you do not plan to reuse your subcomponents elsewhere, you can create something like app-interface and perform updates by calling interface methods. Direct changes of app.data can cause debugging issues.