Well since I literally only ever died for my lack of patience, I think I am a perfect demonstrated example of how this is simply not true. There's no way you're going to be able to disprove my very own (and others, as you read above) experience with the game. You'd just be arguing for no reason
There is never a time I walked into something I had no way of avoiding the first time. The only boss I consider trial-and-error to any degree is Maneater, and not even because I didn't know what to do with them. He's just a bitch to beat period. I even beat most of the other bosses I encountered on my first go. it took a little patience and I always made sure I was heavily prepared going into every encounter. Because unlike games which are actually trial-and-error, this game lets you prepare for almost anything if you take your time.