User experiences are the best way to see if the design is good or bad. People who use any design on a daily basis can tell what works for them, and what does not work. Interestingly, not always the designs work for the users. For that purpose, the users avoid them and find the most practical way for them. As you can see on these pictures, there are differences between the users experiences and the initial designs. Consequently, the users make additional ways which mostly save them time and effort.
User Experiences vs Planned Designs
Finally, the designers should always be careful and focus on the needs of the users of their designs.