Yes, seems like such an odd oversight from Google. They want you to subscribe to channels, but after even moderate use over a few years, you end up with a massive list of subscriptions. I guess it’s not actually an oversight, the bad UX (for finding specific content) is probably on purpose, they want to funnel you through their suggestions. But still, surprised they don’t include a way to organize it.

I use an extension called PocketTube to organize them – but it stores data locally and doesn’t sync very well, so it wouldn’t fit your use case.