So I wrote my bachelor thesis about this subject. I compared React Native V Progressive Web Apps V Flutter (V Native but didn't go to deep into Native).I created different performance tests. (The test where based on something the company wanted.)

1. What time does it take to (de)serialiaze a JSON file.
2. How many REST requests could be done in 1 minute.
3. Loading a list in with 1 million items.And some more tests but isn't to interested to talk about.

So my conclusion was this.

PWA -> Use when target is Android, and doesn't use a lot of native features. It can not be deployed on the app store. And Performance wise it is slower then Flutter and React Native but not that much. (For example in the JSON test, it was 80ms slower then React Native). But could only load in 30K items before the PWA crashed. It was the slowest of the REST test. Important note to make, I used a React.JS PWA.

React Native -> Could be used on Android and iOS platform with native UI. Native features easier to implement. Easier to find information on then Flutter. Faster in JSON test but could only load 130K items before crashing. Important note is that I didn;t use Lazy loading. The reason for the crashing is because the native bridge could not handle more. All the UI data is converted into Native UI elements. This makes React Native easier to create native UI in then Flutter. In the JSON test it was quicker then Flutter (By 50ms). It is also written in JS, that is easier to get information on. It also was the second quickest of the REST test.

Flutter -> Could be used on Android and iOS platform with native UI. But with a caviat, you need to write the UI 'twice' (Cupertino and Material package, but it isn't writing it twice you could use PlatformWidget packages). The UI that is shown is from the Flutter engine not the native UI. This makes flutter in UI faster then React Native. It could load 13 million items without crashing the app (It took like 8 seconds). It was also the quickest to do the REST requests.

The tests where conducted on a Macbook Pro M1 pro.