Huge speed differences between Android and iOS

When running in production mode ionic cordova build android --prod --release there are huge differnces in speed. My App itself includes mostly static content. I use the latest versions of ionic and all the pages are lazy loaded. There are also interactive elements in the form of quizzes. So I would expect it to be fast.

The app loades quite fast, the spinner of the splash screen is barely starting and main page is already there. But it takes like 5 seconds until the app can be interacted with. All interactions have a noticable delay. During the quizzes the app starts getting slow and sometimes interactions take more than 10 seconds and the app becomes unusable.

When I add the crosswalk plugin the app feels three times faster. It feels almost native. All the delays are much shorter, also during the quizzes the before mentioned slowing down does not occur.

I tested this on 5 different devices which have all different capabilities and the results are the same.

It saddens me to say since I’m not an Apple fan, on the iPhone 7 the app runs amazingly fast. Everything happens instantly. The app loads in one second and can be interacted with right away. Just how I would expect it to be everywhere. I really feels native. This difference was a total surprise.

The question is what can be done on android, or what event happens in the android web view that blocks the main thread? Regarding the webviews I would expect chrome to be faster than safari how come there is such a difference?