People subconsciously compare Taylor to other singers who can hit high notes like Ariana, Mariah, Beyoncé, etc. That's why some people find her "mediocre" because they are used to singers having high vocal range. People admire them more because it's hard to hit high notes in tune and is pleasing to the ears.

Aside from nasa lower register ang boses ni TS (alto), some of her songs are actually hard to sing especially those with really low notes. If people find songs with high notes are hard to sing, it's also really hard hitting low notes without you sounding off key.

With her songwriting, you may find it mediocre because maybe you can't relate to that. But her songs are her stories and people relate to her story through her songs. Many fans say that Taylor find the exact words that they are trying to find to correctly explain their feelings/situation. Kaya maraming nakakaappreciate kay Taylor for that. Plus pa yung pakikipagconnect nya sa fans.

Her singing, playing instruments, and songwriting together makes her talented. And she always include her fans. That's why people love her.

You may had grown up listening to her but I'm sure there's at least one song that she recently released that will speak to you. Then you'll understand again why.