Full confession, I have never been a big fan of 'the t-swift', before or after her shift from strummy country-pop to trendy dance pop. I do like "Love Story" and "I Knew You Were Trouble" though, even though they're kinda dumb.
That's really what Taylor Swift is best at: songs that are dumb but fun. Like "We Are Never Ever Getting Back Together". That's a stupid song, but it's FUN stupid, it's FUN to sing along to "Weeeee... are never ever ever... getting back together". I mean, fun for teenagers. Not me, I'm an adult person.
When Swiftaylor tries to be dark, it really just comes off as immature. Take the bridge: "I don't trust nobody and nobody trusts me | I'll be the actress starring in your bad dreams". I'm just thinking 'Well, maybe people'd trust you more if you weren't caught lying'. And 'bad dreams'? Old Taylor is dead but the edgy new Taylor can't even say "nightmare"?
And that's really the biggest problem with this song. It's set up like an edgy diss track, when it has no teeth at all. Compare it to Remy Ma's Nicki diss, which brought those #receipts and kept bringing them the whole track. Is it fair to compare a pop song to a rap song on lyrical detail? Not totally, but it does illustrate the point that "LWYMMD" doesn't name names, except in the vaguest terms. If you look at the genius page right now, you'll see people saying the song could be about Kanye West, Kim Kardashian, or Katy Perry, but it's just not clear. So it becomes just a general 'unnamed person is bad' track that might as well be another 'my ex broke up with me song'. And that would be fine, if the song itself wasn't broken.
First, look at the lyrics, removing all context: "I don't like your perfect crime | How you laugh when you lie | You said the gun was mine". Crime/lie/mine is a super basic rhyme scheme (It took five people to write this???), and the image they create is totally disconnected from any kind of reality - someone's accusing Taylor Swift of murder? and then her only reaction is "isn't cool, no I don't like you". Weak!
The beat isn't terrible, but there's a lot of weird decisions. Like how the first verse is percussion only, and there's no transition to the piano-driven pre-chorus, even though there was a perfectly suitable transition effect used at the thirty second mark when a new drum comes into the mix. And interpolating "I'm Too Sexy" was just dumb. That song is one of the (enjoyably!) goofiest songs of all time. Even people who don't recognize it are going to subconsciously associate that goofy mood with the attempted seriousness of "Look What You Made Me Do", which takes away from any power the song might have had left.
In conclusion, the only way that the song works is if it turns out to be some kind of meta-diss. Like, "Look what you made me do, you upset me so much that now I can't recognize a bad song".