Very good reading,

I really did not understand a 100% your videos, but i have to tell that it was very interesting, and that i learned few things. Thank you

To be honest, it doesn't really matter. Most users will use third-party apps that use cross-platform frameworks and thus will most likely be the same-ish on both platforms. Apple have a slight avantage by having a bigger Apple-only developers base than Google and they will fully use Swift and follow Apple UI. You don't see that outside Apple's devices and so why paying developers to make these apps if you have to make a different app for the rest of the world? BTW, Google have it's own open-source cross-platform framework with Angular and even provide Flutter as a UI/Render to fully make Material apps on any platforms if you want. Yet, it still rare to see Material UI outside of Google.

Very good explanation

I think you can work a little bit hard to explain without reading...