I use the language immersion for learning languages. And with the streaming platforms you can't get cc captions in the original language. There is many foreign media thay is on the platform but not on your country, there is extension that are useful for making flashcards or small clips, but for some reason you can't watch whatever you want to watch in the original resolution if you're on the browser and if you use linux they dare to limit you to 720p. Compare this to just downloading anything you want and using mpv with any extension you want that does whatever you want it to do.
Imagine my dismay to find out Crunchyroll does not offer Japanese subtitles for anything.
Netflix is a little better in this regard, but Neflix in particular goes out of its way to obnoxiously clutter the screen when I pause...even though I paused specifically to try and read something on screen or mine vocabulary from subtitles.