After going on an hour-long subbing spree (you'll see), I found myself with 57 subscriptions. I might have a YT problem. But YouTube's problem is that they don't have a default organization function! I'm following makeup channels, fashion channels, plain ol' entertainment channels like #GoodMythicalMorning (GMM), and gaming channels, all thrown in together as if my Netflix subscription is ending and they're on the last Ark! (Don't worry, Netflix, I still love ya.)
And of course, my first response is to Google around and find a handy Chrome extension that sorts those subscriptions into collections, just like the old YT did. The Youtube Subscription Collection Manager is everything I dreamt of and more--not only can you sort your channels into folders, but you can assign them premade icons, or give them your own; turn off which collections you don't want to see; and autoplay all the recent uploads of any collection! It's really satisfying that file organizer twitch I've had for the past few months. Does no one else dream of a perfectly organized office? Anyway...
There's also this super efficient video showing how to use the extension, as if it wasn't easy enough!