I once had an interview with a YC company where I didn't believe React was necessarily the right fit for applications with simple DOM manipulation, like one I had worked on. I pointed out that you can outperform it when you know exactly what needs to happen to the DOM, like in this example, continually appending new elements. React overall is great, but people need to realize that there are faster React like frameworks and sometimes it isn't faster; however, you normally get simpler code to reason about and less code to maintain.
It's always a trade-of between speed of development/maintenance vs performance. I think React is the best good enough compromise there is. It's really fast and a joy to work with. But obviously, in certain very specific cases, vanilla javascript where you have 100% control over the javascript/DOM will be faster, there's no arguing about that.
