The advantage of using a database, be it SQL, Dataverse, etc. is speeding up the flow of data by breaking it into tables. A core function of PowerApps should be easily connecting these separate database tables live. Most hardcore developers will not look to use PowerApps if it is only fast and easy to use when utilizing SharePoint with all of its limitations. SharePoint is great, but it is no Database. More like an upgraded Excel list.
I would like to put the idea for combine tables the easy way and use it in a delegable function too.