I am an android developer, and I've made several apps on the Google Play Store. I'm currently working on my first game, which is just a simple RPG for android, that I'm coding in Java with the android SDK. I went to an indie game conference recently, and one of the veterans, asked why I didn't use Unity or another game engine to build my game, so it could be easily ported later on. Which got me to wonder if I should use a game engine, since I do want to port this game to other platforms.
So, my question is, should I try to adapt to a game engine to make my future projects, if so, which game engines should I look into?