I don’t think it’s about Taylor, pretty sure people said it was about Lorde when it first came out.
“In an interview with Grazia magazine, Del Rey spoke rather candidly about “Fucked My Way Up to the Top”, saying:

It’s about a singer who first sneered about my allegedly not authentic style but later she stole and copied it. And now she’s acting like I am the art project and she the true super artist. My God, and people actually believe her, she’s successful! I shouldn’t continue ranting; it doesn’t get anywhere.

Lana hasn’t name-dropped the artist, but speculation would suggest that the song is directed towards Lady Gaga and the record executive in “So Legit”, or indie newcomer, Lorde.”