How to Disable Netflix's "Are You Still Watching?" Prompt on Desktop
If you are using Chrome or any Chromium-based browsers like edge which supports Chrome extensions, you can use this Chrome extension "Never Ending Netflix" or "Netflix Pause Removal". Netflix Pause Removal is made to only remove this still watching prompt whereas Never Ending Netflix also provides the option to skip title sequences, ending credits, Auto Play Promoted Videos, etc. If you are looking for a non-distractive binge-watching experience, I highly recommend you to use Never Ending Netflix.
Anyhow Never Ending Netflix add-on isn't available on the Firefox extension store, so you can use the Netflix Pause Removal add-on.
Disable "Are You Still Watching?" Prompt on TV and Mobile
Unlike on the desktop, there's no option to stop this prompt on the TV and Mobile. Anyhow you can either engage with the app with things changing volume, skipping the title sequences or just manually starting the next episode by stoping the autoplay feature. You can disable the autoplay feature for each profile by selecting the profile > account > playback settings and turn off "Autoplay next episode in a series on all devices" and click save. That's it, now all you need to do click on the next episode button.
Updated: November 26, 2021