There should be feature of "Quick View" as same as available in Dynamics 365 CRM.
So we dont have to manage new screen to see Lookup Record's other field's values.
In my current scenario whenever user want to see selected Lookup record's all information, I need to place button on current screen. So whenever user want to see details of that selected record, they can go to new screen by selecting button and that selected record's detail will be displayed in this new screen.
So if "Quick View" feature can be added in PowerApps, it will reduce use of new screens and components and will make PowerApp a light weight app.
This same functionality should be achieved in PowerApps, will reduce the extra usage of new screen and also user friendly - Whenever user want to see details, they can see the details on same page not need to extra click or move to new screen.