New build I need to understand the advantage of per-made builds


So me and a friend are building a IOS/Android app and we have choosen ionic because the apps look great. I just finished building a app for my job with cordova so I am not new to cordova and building plugin’s. I was wondering what are the advantages of using the template which ionic provides rather then just picking my own JS/html technologies to utilize? In true Cordova you just get a simple web server with a www folder to place your webapp in. Why do I want to use ionic’s system? Is their a advantage?