Taylor = Gaga > Adele > Beyonce > Britney.
Taylor and Gaga are almost autocratically invested in their music, where every song is imbued with their own essence. Adele isn't quite the "this is how the song has to sound" type Gaga and Taylor are, where the production of others is more collaborative.I think Beyonce is not as great at songwriting as she likes to believe but I do believe that for her, it's less about the actual song and more about the vision of her work. She might not sit down and write every song, but they have to adhere to her plans. Britney is more or less a pop product, there are genuine moments of artistry in her catalog - but mostly it's about churning out a hit.
I think Taylor and Gaga are the real "in the trenches" types when it comes to their material, whereas Adele is more of a lyric-penner. Bey is more about the entire body of work and Brit is just...there are occasional moments but I don't think she's ever really had a chance to do her own thing. In The Zone is probably the closest you'll get to seeing genuine songwriting from her.
