Grayjay Desktop App

The best feature of alternative YT clients IMO is "multiple subscription lists". I have so many subscriptions, when using the official YouTube app or site the "subscriptions" feed is overwhelming, and I prefer not to use the algorithmically-generated "home" feed. Since YT has kind of become the de facto "place to upload videos on the Internet", video topics are broad enough to constitute multiple web sites, and I like to be able to filter channels by topic rather than having them all grouped together.

If you're opposed to using a separate app just for this, you can achieve something similar using an RSS reader and YT's official RSS feeds (which I'm surprised they still publish tbh).

Reddit had the same issue not too long ago. I remember a popular post where a user described their workaround of creating an account for each field of interest. To Reddit's credit, they did implement custom feeds not to long after, which lets you group batches of subreddits. Not something I'd expect YouTube to do.