Cant apply your electron suggestion to Ionic (unless I’m missing something?).
Ionic itself is a WebView, so you can’t open a webview in a webview – the closest to this would be loading an external site which has an iframe of the twitch embed, which ultimately gets blocked anyway.
You can open an in-app browser, but that’s a fullscreen thing that cannt be resized and thus wont be used (realistically) to embed a stream in the app.
One person mentioned that it works on Android, but not on iOS, but didn’t elaborate further.
Second paragraph
On Android its working perfect but in the iOS App the iframe will not be shown and no player is available. Just a white screen.
The only workaround, and I say that as a stretch, would be to create a custom plugin for capacitor which would resize the main capacitor webview to make space and stack another WebView in the UI stack - but this is far from ideal. That has to be some sort of workaround for this.