Taylor doesn't make music for little girls or tweens, Taylor makes music for people her own age, I've been listening to her since 2008.
The concerts themselves are an experience, dressing up for them to reflect various songs and albums, much like people cosplaying at conventions has become a huge thing via social media and the giving of friendship bracelets. Taylor didn't start those things it spread via the fans themselves, along with specific chants etc that the fans do much like global football fans.
The hype about her is less about her music or even song writing skill but over her as a person. The things she stands for, the generosity (did you know she donated thousands of dollars directly to fans who were struggling over the pandemic).
She (and her team) are also masters of marketing and social media in ways that others aren't. The relationship with Taylor and fans and the rabbit hole of clues relating to new work, hinting at things 3+ years in advance and knitting together patterns and links between songs, albums and tours.
There are something's about her, as a brand I don't like like repeatedly releasing versions of one album in different guises encouraging fans who want to support her to spend ££££ as different versions have different songs on them which is just money grabbing.
There are several documentaries on her on Amazon and netflix if you have access to them which might give you a more rounded view of her if you actually want to find out more rather than just start another thread against her which we seem to have daily.
I think top tickets to events are increasing in value anyway £300 seems pretty standard for a big star now, other sell out events like the FIFA world Cup and the US super bowl tickets go for £1000 each and that doesn't include losing a good chunk of seating as it's obstructed by screens and staging.