It's a bit more subtle than that. Newpipe and youtube-dl don't use the youtube api. They emulate browser behaviour AFAIK. That's probably the biggest reason the

It's a bit more subtle than that. Newpipe and youtube-dl don't use the youtube api. They emulate browser behaviour AFAIK. That's probably the biggest reason they haven't received some form of a letter in general. That they won't be allowed on google's own store is actually not that interesting. The fact that newpipe managed to make a more functional app in a lot of ways than the official youtube app (and I don't mean just the RED functionality) without using the youtube API is quite commendable.