They aren't intentionally hard and frustrating, they are simply challenging and punish your mistakes. Deaths are very rarely cheap, it's all down to you.
First DS is still very much worth it as the Remaster is excellent and solves the fps issues that plagued certain areas of the original. The controls are certainly not irritating? Not sure where that comes from tbh.
As I've said before, my favourite series of games ever so I'm a bit of a fanboy but I dont think youd go wrong with giving one a spin, particularly if you like immersive fantasy worlds.