Why was that thread closed, I had just finished writing something
As someone who knows literally every song available, both released and unreleased, from each artist's discography, I can safely and honestly say Taylor. Gaga has some good lyrics, but gaga at her best is probably just as poetic as Taylor at her worst. Plus, gaga has some awful, awful, awful lyrics that are just plain messy, whereas some of Taylor's are just bad. Taylor is a songwriter. Gaga is a pop songwriter.
And which has been praised countlessly for her songwriting? (By actual people who matter; not biased Stans)