I highly doubt that one can build a ReactJS app that loads faster than a Svelte one. I encourage you to try and share it. This is coming from someone that is a backend engineer that doesn't really do JS, but have had to for my own personal project and both perf and the subjective bit of expressiveness and joy of writing are important. Contrary to popular belief, people think that Svelte is trading perf for ugliness and lack of expressiveness.