Do people usually do all tasks before next area

I tried focusing on progressing the story during my playthrough thinking I'll come back later to do more of the exploration stuff but I got my ass handed to me by the midgardsworner thing in the swamp. I then proceeded to go do all side tasks saving the quetzalcoatl and beach cave wolf for last. Is it normal to have to do all tasks in an area to be high enough level to continue to the next areas for all of the game or is that just for the grasslands to get you to learn about all the world objectives. I'm playing on medium difficulty and I'm not sure if it's just me sucking at the games bossfights that's making progressing the story harder