I'm not entirely sure what the user expected was going to happen. Unless I drastically misunderstand, NewPipe lets a user see YouTube videos with neither ads nor a premium account. Of course that's going to be a TOS violation.
Itt doesn't render the ads, but Google should have no idea how to associate the downloads with a Google account that it can punish. The fact that (the poster alleges) Google has managed to associate his account with his NewPipe activity seems draconian of Google...
Even without ad blocking, simply circumventing CSRF and hitting API endpoints is usually a breach of any TOS by itself, especially one that provides its own clients (or has occasionally refused to, see Amazon FireTV).
Those downvoting the parent, can you add to the discussion?
By API I don't mean published API. I mean it subverts the normal client usage and makes calls directly, masquerading as the intended client. Internal API if you will.
This pretty much is piracy - streaming videos without paying for them to the creators.
For some strange reason not paying for YouTube content and bandwidth seems to be just fine here on HN as opposed to doing the same on iTunes or other services.