It's weird to see things like "definition of pop music or things that are popular etc" as if it's some black or white thing which is why it reeks of people who have a disdain of anything just because it is popular and that's obviously a super dumb way to decide what you should like or not. There's no definition and no such thing that only bland and inoffensive or whatever can be popular. Depends on who you are talking about.
There are various definitions of pop music and pop culture.
This is a conversation that a always get people defensive and replying by calling people snobs, hipsters etc.
Think of soap operas v theatre. Soap operas are huge, have a massive commercial value and consistent huge audiences. Most theatre only exists with arts Council grants, but it's better on every level.
Analogy aside, Taylor Swift is increasingly moving towards being an actual soap opera.
She has actual musical talent, but at her level so do lots of people.
I have worked most of my life in the music industry and I could praise her all day long for various things.
Pogue's Marvel movie comparison is apt. Compared to the endless stream of shite that I could watch with my kids when they were 12, Marvel was a blessing. Taylor is Marvel, hugely successful, slick as hell but formulaic and ultimately artistically quite unimaginative.