Adele isn't ahead personally. She's only done two albums. She's an amazing talent, but when she has a few more albums under her belt, maybe she could be well ahead. For me her impact only surrounds that one album which 21. To be well ahead with your contemporaries, you need to make an impact in several different. Whether it is your image, supporting particular issues etc. Like Madonna.
I can understand why Rihanna and Taylor are. Taylor is the princess of Country and has taken that genre by storm, and no one has done that since Shania and Faith Hill back in the 90's, while Rihanna is the chameleon of pop music and taking on so many different genres which is something her rivals are not doing. The likes of Beyonce, Britney etc are still churning out the same type of music. You need to amp it up. Like Madonna