Making music at any professional level is extremely hard work. Touring and dancing and hosting shows is even harder. It requires a substantial intellectual capacity and stamina to achieve. You either have these things yourself, or you are propped up entirely by others who have them and are invested in you for money's sake. Given Charli XCX's background, it's not actually surprising that she, in fact, has all the talent, skill, and intellect required to do this stuff herself.
Editing to add: Another place to look to learn that people with this skillset often have very very deep inner lives is Dua Lipa's book club podcast (https://www.service95.com/tag/book-club). As someone who used to run these kinds of in-depth interviews, I can say, she is damn good at it.