AFAIK, React is a Single-Page Web Application that refreshes everytime something changes. It's benefits are fast load times and lower overhead because it ONLY updates things that are changed on re-render, but the downsides are that it relies on other libraries for things like multiple pages, etc.
So for it to be a Windows System application, yes that's fucking attrocious. Did you ever hear how angry people were about the Warcraft 3 update that added a bunch of webapp nonsense and bricked a lot of people's old copies? Well, that's basically what Windows 11 did.