In my experience, the most challenging part of PowerApps development is dealing with data from related tables. Getting data from a related table often involves complex coding or use of collections to consolidate data. Some competing development platforms use a data modelling layer where relationships can be defined and then referenced in code using a simple syntax (eg, childTable.foreignKeyField.parentField) without the need to explicitly manage relationships through independent calls to each table in code. If PowerApps is to become a true low-code development tool then it needs to find a way to manage relational data in a simple way, not through code. If PowerApps wants to move ahead of the competition, then selecting fields through a visual representation of the data model would be ideal.