You can consider another app:
though I haven't tested any of these.
Or you can consider another browser, namely mobile Firefox. Based on solution given here for iOS:
- Navigate to youtube.com (in Firefox)
- Find and play your video
- Hit the three-dot menu button
- Tap the Request desktop site
- When the page reloads, play the video again
You're done. Slide down the notification center to find video controlling buttons there:

Replicating the same steps in mobile Chrome turned out to be ineffective.
There's one important note here. Depending on how you're watching given video:
- Using suggested Firefox Mobile or trying some other browser.
- Watching in mobile mode or requesting desktop site.
- Turning off screen immediately or waiting until it gets turned of by itself etc.
your wideo (or actually audio from YouTube) will:
- play forever,
- stop immediately,
- stop after 5-8 minutes.
And you will be able to enjoy interrupted experience for long time or you will be forced to turn on and off screen after each 5-8 minutes (like in my case).
Because, no matter what I did, I failed to achieve interrupted, few hours long experience, I was forced to use additional solution (provided above) and install Fake Standby app.
Keep in mind that in current version (November 2020) Fake Standby is causing some weird interference to Google Calendar.
This answer is based on this answer at Software Recommendations and my own blog post.