[acchow]

Objective-C actually gets compiled down to machine code at compilation down. When you download an app from the app store, there is no more Objective-C.

RN doesn't "compile" the Javascript to bytecode or machine code. Instead, the closest competition you could get from RN is a JIT. But AFAIK iOS doesn't allow a Javascript JIT to run, so the JavaScript running is not being JITed to Bytecode.

Even if you assume that iOS allows a JS JIT now, you still have a JavaScript->Native bridge to cross. This adds a performance hit that Objective-C does not have.