it optimizes for not thinking about loading states, and the way it's normally used (hook fetches data, suspends) results in you having to go out of your way to add a loading state near the component that suspended, as you have to create an intermediate component and a loading component, splitting what should be a single concern into several, and it results in a lot of duplication that previously could be addressed by just having an `isLoading` prop

not thinking about loading states hurts ux and perceived performance

edit to clarify: i like hooks (though people abuse them) and believe react has generally always been best-in-class at thoughtful interface design. suspense breaks with that imo