compose multiplatform is fulfilled by jetpack compose on android, so the performance should be equivalent. Regarding RN, it is pretty simple, compose mutiplatform is going to run circles around any RN app since you don't need to wait until a foreign engine (Hermes for JS, for example) starts before rendering your app. Unless the RN modules used in the sample are properly coded for lazy loading, the render operations are scarce, and the workload is fixed or limited, RN will be far slower. I can't speak a lot about Flutter, I'm not really knowledgeable about their internals.