Difficulty depends a lot on class & skills. As a mage & archer, I had a pretty easy time the entire game. As a warrior... not so much, until I had some ranks in Life leech & Regenerate.
Anyway, Divinity 2's gameplay is not really unforgiving. It's rather typical for the genre... most action RPGs (Diablo, Titan Quest, Dungeon Siege) have level-based gameplay.