Why does the .apk take up ~26MB, but when installed the app takes up 116MB

Hello, a few days back I posted about a large apk size with a blank project. Now I managed to reduce the .apk file size of a blank project to ~26mb and ~6MB .obb file ( Screenshot - 15343fa61d3a7b51bf8abf330bc2465e - Gyazo ) But when I install the app on my phone it suddenly takes up about 116MB, why does the size quadruple? Is there any way to reduce that?