Not even speaking about all the ads in the default YouTube app without a subscription.
The app is basically useless in my opinion. It defaults to freaking 240p for every video. My phone is definitively not the problem, also not the Internet connection. Watching in Firefox on the same connection gives me normal expected quality.
This was better on some “feature phones” without touchscreen!!! YouTube app works and playback is in 720p / 1080p
They do not distribute any binaries to avoid copyright issues I believe. There are some telegram channels doing what you described, but I wouldn’t trust it enough to use it.