Google killed off most YouTube apps some years ago, in favor of YouTube Red. Google stated those apps being in violation of the YouTube ToS, but even when those apps removed the violating features, Google would find new reasons for keeping them off the Play Store. Well, and then they would sell those supposedly ToS-violating features themselves, as part of YouTube Red, like for example background playback.
Since then, most YouTube apps are knowingly in violation of the ToS or at least not holding their breath that Google might decide so.
So, either they don't use the official YouTube API, like NewPipe and LibreTube, meaning you can't log in with those. Or they don't put in too much effort, like ReVanced just being a mod of the official app, so that won't have the features you want. Or I guess, they just risk it for quick profit, like Grayjay, but that will probably get shut down before they have such features developed.
Theoretically, a non-ToS-violating app can exist and could be distributed via the Play Store, but it would basically not be able to integrate any unique feature.
So, yeah, as others said, I don't think this exists.
You could try some alternative methods like:
- Use two different apps, logged into two different YouTube accounts.
- Utilize an Android work profile to be logged into different accounts with different installations of the same app.
- If you just care about having different subscription feeds, use RSS feeds instead.
- See if a non-Google operating system is less shit at this.