I must say that they are quite unique and portrays a character's view on numerous things. For example, I was checking out Zhongli's character story, where his brief is given how his relations are with other people and his character traits. Not only that, there's a section about his Gnosis that's given on the page, and it's interesting to give it a read. I won't spoil any of the stories about him here, but if you don't have him yet, you can hunt on Google to know about his character details. In the case of other characters, there's a section about their Vision or something unique to them. For example, in Kaedehara Kazuha's story tab, you will see a section about "Vision Shell" and his own Vision that describes them.  While you will find Vision tabs for other characters, in the case of Archons, they have Gnosis tabs where you can read about their Gnosis. I find it unique that you can hear about characters' opinions on other characters. Personally, I love Klee's voice-overs because they are jolly and full of innocence. Going through her voice-overs brightened my day up, and I never felt bored of them. It's an awesome feature to learn more about your favorite characters and know about their lore that helps you to connect dots in the story.