[Latty]

I don't think it is that simple. When it comes to not playing the ads, I agree that is a problem. When it comes to the features, I think it is different.

One of the features is background playback of audio from videos. On the desktop, that's a feature that exists thanks to your window manager. Is that unethical?

It isn't stealing to use another method to get a feature someone is selling you, any more than using a third party DVR is stealing from a company offering you one as part of a more expensive package.

They have implemented the feature independently, and are providing it as a way of doing the same thing as something YouTube is selling you, I don't see that as a problem.

(NewPipe also has features that YouTube's app just doesn't support at all, like higher speed playback than 2x).