If you cannot get a group of people for whom your product is designed for to generally agree that your design is good, it’s not good.
If you cannot get a group of designers to generally agree that your design is easy-to-use and well-crafted, then it isn’t.
The greatest frustration is feeling like you’re getting too much criticism from too many people (which, according to #2, means your design is not yet good). This is either because a) you’re working under too many constraints b) you’re not exploring solutions broadly enough, or c) the problem is beyond your current skill level.
Obviousness comes from conforming to people’s existing mental models. Don’t waste time reinventing common UI patterns or paradigms unless they are at least 2x better, or you have some critical brand reason to do so.
Better design does not mean more design. Often, the most obvious designs are invisible.