Nicky sounds fine, as usual. Nothing particularly interesting or focused lyrics-wise (oh my a Biggie reference, woo…) Katy is not remotely a bad singer, and the few moments on here where she’s singing rap-style lyrics – “like a coupon – expired” aren’t awful… but that one line previously mentioned is about the ONLY memorable thing in the song… The rest is literally gone out of your mind almost instantly. While the theme of the song isn’t unthinkable for some dance-y pop song, it just doesn’t seem developed beyond surface level.
Beat is good, but that’s kind of like being impressed with a kid putting their name on their homework; it’s a bare minimum requirement. Dance to it when it comes on, but you’ll forget it as soon as it’s over, and probably enjoy the next song much more.
…And the Taylor Swift drama/conspiracy is face-palm worthy, at best. Childish, uninteresting, and even potentially forced.