Yes, some famous singers get by on their looks verses their raw talent. There are a lot of women in multiple genres, that when its time to perform live sound awful. Their appearance makes them appealing to the mass public. People often overlook the fact that they're not the best singer, if the song is great, and they look awesome.
Auto-tune and other things of that nature can make almost anyone sound like a pop-star these days. Therefore, talent hardly makes any famous singer stand out. It's how well that singer is marketed and promoted that determines how much recognition he or she receives. And if that singer is marketed for his or her sex appeal, that singer will arguably receive more exposure and recognition because society appears to respond strongly to that type of promotion.
There was a time when there was more emphasis on talent than the looks and persona of a singer. Those days are coming to an end. Look at most of the top singers in the world today. Most of them cannot even sing that well, but you constantly see them being praised about their looks and what they wear.
An artist can be good looking and have great music but if they are not marketed well then nobody will simply know or care about them. That's why even good looking artists can sometimes act provocatively and acting in a sexual mannerism because even talentless artists need more than beauty for recognition. It's about making yourself known. People remember explicit videos and performances, not a pretty face.
Sure, physical appearances may play a large role in the success of performers, but it is not what it is all about. Many people have made debuts and a big impact on the entertainment based on their pure talent alone. Take Susan Boyle for example. People judged her by how she looked at first, but the moment her voice began to sing and it traveled across the stage, the entire audience was stunned. Afterward, she sold thousands of CDs and her name because a huge title. Physical appearance may play a role, but pure talent definitely continues to shine.
No. Famous singers do not receive recognition due to physical appearance rather than talent. Many famous singers, including most notably Adele, do not have attractiveness based on societal standards. This holds true for a majority of male performers as well. However, success does lend to the perception of attractiveness which leads some to classify these artists as physically attractive. Being attractive and having talent is the optimal formula for success, though it is not a necessary prerequisite.